Plone

Plone is a mature, secure, and user-friendly content management system (CMS).

Plone was first released to the public on October 4, 2001.

Plone has the maturity, stability, and reliability of an application maintained by open source developers with decades of experience, while continually evolving and adapting to modern technology.

Lots of customizations can be made trough-the-web, such as creating content types, themes, workflows, and much more. Plone may be extended and used as a framework on which to build custom CMS-like solutions.

Plone works as a

• Full-featured server-side rendered HTML CMS.
• React-based frontend for editing and viewing content, backed by a server with a REST API.
• Headless CMS server with a REST API, allowing a developer to build a custom frontend with their chosen technology.

Installing Plone

Plone is available on Linux, Microsoft Windows, macOS, and BSD platforms.

Plone may be run as a container in the cloud with Docker and other Open Containers Initiative compliant platforms. Example Dockerfiles and base images are available.

Install Plone by choosing an option from plone.org

Documentation

Consult the official Plone documentation with information for different audiences.

For trainings comprehensive Plone training material is available.

What is Plone?

Plone is a ready-to-run content management system, offering a complete set of features needed by a wide variety of organizations.

Security is built into Plone's architecture from the ground up. Plone offers fine-grained permission control over content and actions.

Plone is easy to set up, extremely flexible, and provides you with a system for managing web content that is ideal for project groups, communities, websites, extranets, and intranets.

• Plone is easy to install. Several installation options are available for either your local machine or on servers in the cloud.

• Plone empowers content editors and web application developers. The Plone Team includes usability experts who have made Plone easy and attractive for content managers to add, update, and maintain content.

• Plone is international. The Plone interface has more than 35 translations, and tools exist for managing multilingual content.

• Plone follows standards and is inclusive. Plone carefully follows standards for usability and accessibility. Plone is compliant with WCAG 2.1 level AA and aims for ATAG 2.0 level AA.

• Plone is open source. Plone is licensed under the GNU General Public License, the same license used by Linux. This gives you the right to use Plone without a license fee, and to improve upon the product.

• Plone is supported. There are over two hundred active developers in the Plone Development Team around the world, and a multitude of companies that specialize in Plone development and support.

• Plone is extensible. There is a multitude of add-on products for Plone to add new features and content types. In addition, Plone can be scripted using web standard solutions and open source languages.

• Plone is technology neutral. Plone can interoperate with most relational database systems—both open source and commercial—and runs on a vast array of platforms, including Linux, Windows, macOS, and BSD.

Technical overview

Plone is a content management platform with its backend written in Python. Plone has a choice of frontend, either Classic UI using server-side templates or Volto written in modern React-based JavaScript. It builds upon Zope, an open source web application server and development system, and thus on the pluggable Zope Component Architecture (ZCA).

Python is the easy to learn, widely used, and supported open source programming language. Python can be used to add new features to Plone and used to understand or make changes to the way that Plone works.

Plone stores its contents in Zope's built-in transactional hierarchical object database, the ZODB. The ZODB can be connected to simple file-storages, scalable ZEO-Servers or Postgres, MySQL, and Oracle. There are add-ons and techniques, however, to share information with other sources, such as relational databases, LDAP, filesystem files, and so on.

Official Resources

• plone.org - Official website for developers, community, decision makers, and evaluators.
• Plone support - Where to find help.
• community.plone.org - Official community forum, the best place to get help.
• Plone 6 Documentation - Official documentation for developers, integrators, and content editors.
• training.plone.org - Trainings for developers, integrators, content editors, and designers.
• plone.api - Documentation for plone.api.
• plone.restapi - Documentation for plone.restapi.
• Discord - Official Plone chat, voice, and video service.

This project is supported by

License

Changelog

6.0.8 (2023-11-06)

Internal:

• Prepare 6.0.8 final. No changes compared to the release candidate. [maurits] #608

6.0.8rc1 (2023-10-26)

Bug fixes:

• Fix problem when adding a Plone site with a custom INonInstallable utility without a getNonInstallableProfiles method. Fixes issue 3862. #3862
• Updated metadata version to 6019. [maurits] #6019

6.0.7 (2023-09-21)

Bug fixes:

• Register site syndication settings from plone.base instead of CMFPlone. [maurits] #315

6.0.7rc1 (2023-09-14)

Bug fixes:

• Explicitly disable Products.CMFCore.explicitacquisition in Plone 6. [jaroel] explicitacquisition
• Update plone.app.z3cform dependency version and deprecate plone.app.widgets [petschki] #3821
• Updated metadata version to 6018. [maurits] #6018

Tests

• Fix unstable robot test scenario Reorder Folder Contents. [maurits] #3811

6.0.6 (2023-06-27)

Internal:

• Prepare 6.0.6 final release. No changes since the release candidate. [maurits] #606

6.0.6rc1 (2023-06-22)

Bug fixes:

• Fix repairing relations. [ksuess] #3457
• Fix alerts to follow Bootstrap convention. [petschki] #3806
• Updated metadata version to 6017. [maurits] #6017

6.0.5 (2023-05-30)

Bug fixes:

• Fix password validation tests. [tschorr] #3784
• membershipSearch in UsersGroupsControlPanelView should respect many_groups, many_users Option and empty Searchstring |1letter #3790

6.0.5rc1 (2023-05-25)

Bug fixes:

• Do not truncate the sortable_title index [erral] #3690
• Fix password validation tests. [tschorr] #3784
• Updated metadata version to 6016. [maurits] #6016

Internal:

• Update configuration files. [plone devs] 2a5f5557

6.0.4 (2023-04-24)

Bug fixes:

• Prepare 6.0.4 final. No changes compared to the release candidate. [maurits] #604

6.0.4rc1 (2023-04-21)

Bug fixes:

• Prepare 6.0.3 final. No changes compared to the release candidate. [maurits] #603

• Add a last modification time of the resource registry. We update this when changing anything related: when changing the resource registry in its control panel or activating an add-on. This avoids needing a restart before seeing changes when you run in production mode. Fixes issue 3505. [maurits] #3505

• Removed path query from search view when context is site root. [malthe] #3753

• Fixed encoding issue on Python 3 for some mail servers. This could result in missing characters in an email body. [maurits] #3754

• Mockup TinyMCE settings: Fix URLs in TinyMCE external_plugins settings.

  Add the portal URL to external_plugins values for relative and absolute URLs.

  Before this fix external plugins could not be found if they were not added with the full path or a full URL. The path is different for virtual hosted sites and sites directly served from Zope. #3767

• Updated metadata version to 6015. [maurits] #6015

6.0.3 (2023-03-27)

Bug fixes:

• Prepare 6.0.3 final. No changes compared to the release candidate. [maurits] #603

6.0.3rc1 (2023-03-23)

Bug fixes:

• Remove unused template send_feedback_confirm.pt. [jensens] #3122
• Moved the assignment of Plone Site Setup permissions from zcml to GenericSetup rolemap.xml. This assigns the permissions on site creation instead of Zope root where the Site Administrator role does not actually exist [ewohnlich] #3223
• Fix deprecated imports. [jensens] #3733
• Fix userlisting batch/showAll in group membership template. [petschki] #3738
• Implement pat-checklist for groupuser management. [petschki] #3740
• Import PloneMessageFactory from plone.base. Removes deprecation warnings. [jensens] #3742
• Fix circular dependency in plone.app.theming on ZCML level. Move permission over there. [jensens] #3747
• Updated metadata version to 6014. [maurits] #6014

6.0.2 (2023-02-27)

Bug fixes:

• Apply Barceloneta upgrades when upgrading Plone. [maurits] #3726

6.0.2rc1 (2023-02-23)

Bug fixes:

• Fix editing modal property of an action in @@actions-controlpanel. [petschki] #3709
• Updated metadata version to 6013. [maurits] #6013

6.0.1 (2023-01-31)

Bug fixes:

• Prepare 6.0.1 final. No changes compared to the release candidate. [maurits] #601

6.0.1rc1 (2023-01-30)

New features:

• Add data-bundle attributes on javascript and styles resources. [aormazabal] #3707

Bug fixes:

• During login, when login_time is invalid, warn and reset it to 2000/01/01. Fixes issue 3656. [maurits] #3656
• When autologin after password reset is enabled, use the same adapters as during normal login. Specifically: the IInitialLogin and IRedirectAfterLogin adapters. Autologin is enabled by default. Fixes issue 3713. [maurits] #3713
• Updated metadata version to 6012. [maurits] #6012

6.0.0 (2022-12-12)

Bug fixes:

• Add help label to create Plone site page for difference between Volto and ClassicUI with link to docs. [fredvd] #3072
• Change the search control panel to select types not searched instead of searchable types. This fixes an inconsistency with Volto. [danalvrz] #3694
• Update default home page for installers for Plone 6 final release. [stevepiercy] #3700
• Updated metadata version to 6011. [maurits] #6011

6.0.0rc2 (2022-12-05)

Bug fixes:

• Fix duplicated <article id="content"> in login form. [petschki] (#3680)
• Fix caching of rendered resources. [petschki] (#3683)
• Update package metadata in pypi. [ericof] (#3687)
• Updated metadata version to 6010. [maurits] (#6010)

6.0.0rc1 (2022-11-18)

Bug fixes:

• Don't create news, events, and users folders for Volto sites. [davisagli] (#3628)
• Fix password used in a test. [davisagli] (#3653)
• Bootstrap fix for numbering .list-group-numbered. See suggestions here https://github.com/twbs/bootstrap/issues/37345 [petschki] (#3661)
• Fix 'KeyError: file' in browser tests on Python 3.11. [maurits] (#3663)
• Updated metadata version to 6009. [maurits] (#6009)

6.0.0b3 (2022-10-04)

Bug fixes:

• Deprecate the portal_properties tool, remove obsolete code (#125)
• Require Python 3.8 or higher. [maurits] (#3635)
• Actually load theme-specified styles CSS in TinyMCE. [Rudd-O] (#3638)
• Minor visual fixes in admin UI [jensens] (#3640)
• Fix aliased helpers [ale-rt] (#3641)
• Fix tests to work with longer minimum password length. [davisagli] (#3646)
• Improve tinymce table settings [MrTango] (#3650)
• Make add classic Plone site button better visible [MrTango] (#3651)
• Updated metadata version to 6008. [maurits] (#6008)

6.0.0b2 (2022-09-10)

Breaking changes:

• Officially drop Python 3.7 support and add 3.10 support. Currently everything still work in 3.7, all tests pass, but beta 2 is the last release where this is the case. See discussion in this issue <https://github.com/plone/Products.CMFPlone/issues/3635>_ and especially this community poll <https://community.plone.org/t/plone-6-0-drop-support-for-python-3-7-and-3-8/15549>_. [maurits] (#3635)

Bug Fixes:

• Moved CSFR patches addressing CMFPlone itself to decorators. [jensens] (3614-2)
• Fixed an issue that prevented the user to select the preferred timezone (#1290)
• Fixed adding control panel action via ZMI. [maurits] (#1959)
• Changed 'Powered by' text [rohnsha0] (#3382)
• Fix active tab in @@test-rendering-icons. [petschki] (#3475)
• Do not create title tag for svg icons when tag_alt is not given. [agitator] (#3536)
• Fixed all known instances of plone.com in plone/Products.CMFPlone [rohnsha0] (#3568)
• Allow access to the macros of the main_template, also from skin templates. [maurits] (#3581)
• Robot tests: be more specific when clicking some elements. [maurits] (#3582)
• Set portal title in registry when creating a new Plone site [erral] (#3584)
• Change test to make sure e-mail is sent in utf-8 [erral] (#3587)
• Fixed 'Site Setup' link appearing on various parts of Control Panel [rohnsha0] (#3599)
• Fixed Inconsistent font issues in Control Panel [rohnsha0] (#3600)
• Fix visual issue with long action name in @@actions-controlpanel. [petschki] (#3601)
• Fixed an error where Main Template (line: 42) referenced plone.com instead of plone.org [rohnsha0] (#3605)
• In traversal.py remove a Zope 4 BBB code, add a comment about bundle traverser and apply black.isort on the file. [jensens] (#3609)
• Suppress warning of intentional deprecated import for BBB. [jensens] (#3610)
• Use plone.base and reduce deprecation warnings. In utils remove functions already moved to plone.base and add deferred import with message. Deprecate correct, where prior only comments or old logging. Some black/isort where touched. [jensens] (#3614)
• Move utils.getQuality and utils.getAllowedSizes to plone.namedfile.utils. This helps untangling circular dependencies. [jensens] (#3615)
• Do not use deprecated calls in actions expressions. ActionsTool and PloneBasetool got an code style overhaul. [jensens] (#3616)
• Updated metadata version to 6007. [maurits] (#6007)

6.0.0b1 (2022-07-23)

Breaking changes:

• Removed our expressions patch. This was a patch to avoid some too strict checks by Zope / Products.PageTemplates. But in Plone 6 it should be fine to be stricter. The STRICT_TRAVERSE_CHECK environment variable is no longer read. [maurits] (#3567)

New features:

• Initially open accordions in resource registry. Hide via JS when no errors occur. [petschki] (#3560)
• Resource bundle dependency on multiple comma separated names. [petschki] (#3570)

Bug Fixes:

• Reduce dependencies in setup.py here, when already fulfilled in the packages where in use. [jensens] (#3572)
• Fix more plone.base related deprecation warnings. [jensens] (#3573)
• Fix adding/renaming resources TTW. [petschki] (#3574)
• More i18n fixes [erral] (#3575)
• Updated metadata version to 6006. [maurits] (#6006)

6.0.0a6 (2022-06-27)

Bug Fixes:

• Remove the use of f-strings for translations [erral] (#3564)
• Fix several i18n bugs [erral] (#3565)
• Fix tests for image_scale download url update. [petschki] (#3566)

6.0.0a5 (2022-06-24)

Breaking changes:

• Remove Archetypes specific isIDAutoGenerated helper. This was dead code not used anywhere in Plone 6. [jensens] (#3487)
• PloneFolder was once used with early Archetypes. This code is dead now and got removed. [jensens] (#3492)
• DublinCore.py was once used with Archetypes. This code is dead now and got removed. [jensens] (#3493)
• Move discussion Key to plone.app.discussion. [jensens] (#3520)

New features:

• Added customisable batch_size for redirects controlpanel [iulianpetchesi] (#1178)
• Add option to use TinyMCE in inline-mode. [pbauer] (#3465)
• Add image srcset's configuration to TinyMCE pattern settings [MrTango] (#3477)
• Add support for images in default search page. [agitator] (#3495)
• Enable auto include of styles to the TinyMCE formats menu. The file has to be named tinymce-formats.css and known by TinyMCE. [agitator] (#3510)
• Add image_scales to catalog metadata. [cekk, maurits] (#3521)
• Sort addons by title [erral] (#3523)
• Show more information of broken relations [pbauer] (#3527)
• Show link to the Volto-migration (@@migrate_to_volto) in the view @@plone-upgrade when the option is available. [pbauer] (#3528)
• SVG image as default Plone logo. [petschki] (#3558)

Bug Fixes:

• Make compatible with robotframework 3-5. [maurits] (#5)
• Explicitly include zcml of more packages. Reorder the zcml loading. Require plone.resource. [maurits] (#3188)
• Remove date range search fix, which was done in Products.ZCatalog. [wesleybl] (#3432)
• fix @@iconresolver to resolve names with "/" correctly (eg. "contenttype/document") [petschki] (#3500)
• Bugfix: Resource viewlet cache took not enough factors into account (like base url). [jnsens] (#3503)
• Moved recently_modified and recently_published skin templates to browser views. [maurits] (#3515)
• Fix for quoted search terms [petschki] (#3517)
• Fix robot tests for updated toolbar [petschki] (#3522)
• Fix rendering viewlet.resourceregistries.js when there are missing resources. [petschki] (#3533)
• Fix tests for updated module federation bundles. [thet] (#3539)
• Remove modal from login and join action. [agitator] (#3555)
• Fix reporting of exceptions in Products.CMFPlone.factory.addPloneSite. [davisagli] (#3561)
• Updated metadata version to 6005. [maurits] (#6005)

6.0.0a4 (2022-04-08)

Breaking changes:

• PLIP 3211:

  • Remove RequireJS.
  • Remove default resource jQuery. It is added to the global namespace via the bundle.
  • Remove support for conditional comments in script and style tags. It's not supported since IE10. See: https://en.wikipedia.org/wiki/Conditional_comment

  [MrTango, thet] (#3247)

• Remove dependency on mockup. Mockup is now a npm package only and as such a dependency of plone.staticresources. [thet] (#3247)

• New resource registry to simplify CSS/JS registration.

  • Completely (almost) rewritten ResourceRegistry based on the "webresource" project.
  • removed >1600LOC.
  • Sane dependency resolution using "webresource".
  • Only "bundles" are registered - support of "resources" and "bundle resources" is removed.
  • Some of the old bundle registry properties are deprecated and unused.
  • Removed TTW compilation of bundles via r.js and less.js.
  • Property merge_with is no longer needed in HTTP/2 times and merging here unsupported.
  • Unique key for delivery is based on hash of bundle file, last_compilation property is deprecated.
  • A new traverser ensures uniqueness.
  • Other related bundle properties are also deprecated.
  • Comes with new, server side generated control panel.

  [jensens] (#3325)

• Remove deprecated.zcml and meta-bbb.zcml. [jensens, pbauer] (#3485)

New features:

• PLIP #3279: Implement modern images scales. Add huge (1600px), great (1200px), larger (1000px), teaser (600px). Amend preview and mini (remove height constraint). [tisto] (#3279)
• Add TinyMCE template plugin to the plugins vocabulary [MrTango] (#3351)
• Implement PLIP 3395 <https://github.com/plone/Products.CMFPlone/issue/3395>_. Moves all interfaces, whole defaultpage, i18nl10, batch, permissions and parts of utils to plone.base. For all imports are in place with deprecation warnings. Along with this a bunch of long deprecated functions, imports and similar in above packages were removed. [jensens] (#3395)
• Add TinyMCE alignment classes, to avoid style usage [MrTango] (#3440)
• Compatibility with z3c.form >= 4 [petschki] (#3459)
• Added support for images in liveSearch results. [agitator] (#3489)

Bug Fixes:

• Fixed evaluating expressions on resources, and especially loading plone.session resources. Fixes plone.session issue 23 <https://github.com/plone/plone.session/issues/23>_. [maurits] (#23)

• MigrationTool: use more standard listUpgrades code from GenericSetup 2.2.0. I ported our special logic there. [maurits] (#220)

• Handle /favicon.ico accesses on Plone sites. (#282)

• Fixed tests when run with zope.component 5+. [maurits] (#500)

• Remove Configlets, Change Member Password and Member Prefs not needed in Overview Controlpanel both Views available via User Control Panel

  the deleton of "Change Member Password" Configlet remove also the issue #3031 [1letter] (#3031)

• Removed no longer used password_form.pt and plone_change_password.py. No longer register now empty skin layers plone_prefs and plone_form_scripts. [maurits] (#3240)

• Fix TinyMCE configuration JSON serialization and cast entity_encoding to a list. (#3247)

• Make author template barceloneta/bs5 ready. Add some CSS classes to Markup. [1letter] (#3290)

• Use behavior-names instead of python-paths in types-controlpanel [pbauer] (#3294)

• Fix broken link in the RelationsInspectControlpanel prepend absolute portal url to links add RelationsControlPanelFunctionalTest [1letter] (#3322)

• Fix missing closing BODY tag in insufficient_privileges.pt [1letter] (#3374)

• Reorganize viewlets after removing the plone.header viewlet in plone.app.layout [erral] (#3416)

• Fix login-help validation [petschki] (#3422)

• Fix info message (char left over) in quickinstaller template [laulaz] (#3430)

• Fix overview-controlpanel view for Gunicorn WSGI HTTP Server. [bsuttor] (#3442)

• Fix detection of initial login time [MrTango] (#3447)

• Updated the list of core profiles that are upgraded during a Plone upgrade. Added Products.PlonePAS and plone.session, and the optional plone.restapi and plone.volto. [maurits] (#3453)

• Remove obsolete css files previously used in tinymce. [pbauer] (#3463)

• Add missing i18n:translate tags [erral] (#3467)

• Remove obsolete combine_bundles and related code. [pbauer] (#3468)

• Enhanced folder_contents robot tests [petschki] (#3478)

• Updated metadata version to 6004. [maurits] (#6004)

6.0.0a3 (2022-01-28)

New features:

• add a new entry in site-controlpanel to change the favicon and its MIME-type The favicon can be a .ico/png or SVG-file [talarias] (plip-barceloneta_lts_favicon)
• The @@plone view exposes the human_readable_size helper [ale-rt] (#3146)
• Allow from warnings import warn and warn("message", DeprecationWarning) TTW, like in Python Scripts. [jensens] (#3376)
• Customize breadcrumbs hook customize_entry for subclasses (like already in global navigation). [jensens] (#3377)

Bug Fixes:

• Cleanup Error Log Form after Review [jmevissen] (#3241)
• Removed management_page_charset support from usergroup-groupdetails page. This is related to deprecated unicode property types, like ustring. Part of issue 3305 <https://github.com/plone/Products.CMFPlone/issues/3305>_. [maurits] (#3305)
• Update Controlpanel Error Log Form Layout Rename ControlPanel Error Log Form View prefs_error_log_form -> error-log-form [jmevissen] (#3393)
• Use label_site_administration instead of label_site_admin in error and mail_password_form templates (#3397)
• Updated metadata version to 6003. [maurits] (#6003)

6.0.0a2 (2021-12-03)

Breaking changes:

• PLIP 3339: Replace z3c.autoinclude with plone.autoinclude. Note: includeDependencies is no longer supported. [maurits, tschorr] (#3339)

New features:

• On Zope root, create Volto site by default. [maurits] (#3344)

Bug Fixes:

• Move prefs_error_log* from skins to browser views [jmevissen] (#3241)
• The Plone site root is cataloged (#3314)
• Fix #3323DX-Site-Root: ZMI Nav-Tree is no longer expandable. [jensens] (#3323)
• Fixes #3337: Remove dead code that won't work in Py 3 anyway if called (cmp). [jensens] (#3337)
• Remove DYNAMIC_CONTENT from translation files [erral] (#3342)
• Remove adapter for index location. [wesleybl] (#3347)
• Use document_view as default for site root. [agitator] (#3354)
• Add missing lxml dependency [MrTango] (#3356)
• Fixes #3352 - dependency indirection on plone.app.iterate [jensens] (#3357)
• In Portal: use security decorators [jensens] (#3366)
• Updated metadata version to 6002. [maurits] (#6002)

6.0.0a1 (2021-10-22)

Bug Fixes:

• Release Plone 6.0.0a1. No changes since previous release. [maurits] (#3341)

6.0.0a1.dev1 (2021-10-16)

Bug Fixes:

• Use HTML5 meta charset. [malthe] (#2025)

• add icon_expr to view/edit action for @@iconresolver [petschki] (#3327)

• Set the "Show excluded items" (show_excluded_items) to False per default. Setting it to True can introduce a performance problem. False should be the default, also from user expectation for the exclude_from_nav setting on content items. No upgrade step! Previous behavior is just kept, unless you override it manually. See: #3055, first comment. Use this registry snippet to set it false::

  <?xml version="1.0"?>
  <registry>
    <records prefix="plone" interface="Products.CMFPlone.interfaces.controlpanel.INavigationSchema">
      <value key="show_excluded_items">False</value>
    </records>
  </registry>
  

  Fixes: #3035 [thet] (#3329)

• Remove typo in ajax_main_template [petschki] (#3333)

• Fix some template issues to have properly translated messages (#3334)

• Updated metadata version to 6001. [maurits] (#6001)

6.0.0a1.dev0 (2021-09-15)

Breaking changes:

• Removed our CMFQuickInstallerTool code completely. See PLIP 1775 <https://github.com/plone/Products.CMFPlone/issues/1775>_. [maurits] (#1775)
• Use Dexterity for the Plone Site root object. This is PLIP 2454 <https://github.com/plone/Products.CMFPlone/issues/2454>_. [jaroel, ale-rt] (#2454)
• Removed dependency on Products.TemporaryFolder. Note: in your plone.recipe.zope2instance buildout part, you must set zodb-temporary-storage = off, otherwise you get errors when starting Plone. See issue 2957 <https://github.com/plone/Products.CMFPlone/issues/2957>_. [maurits] (#2957)
• A part of "Drop Python 2 Support for Plone 6" #2812: Reflect dropping of Python 2 support in setup.py. Bump version to 6.0 [jensens] (#3041)
• Removed folder_publish.cpy script. Replaced with folder_publish browser view in plone.app.content. Removed deprecated transitionObjectsByPaths. [maurits] (#3057)
• Removed Products.CMFFormController dependency. [maurits] (#3057)
• Removed content_status_modify.cpy script and its validator validate_content_status_modify.vpy. Replaced with content_status_modify browser view in plone.app.content. [maurits] (#3057)
• Barceloneta LTS theming (#3061)
• Remove six at all places where used. [jensens] (#3183)
• Remove portal_utf8 and it twin utf8_portal from utils and PloneTool since its never used nowhere. [jensens] (#3183)
• Remove meta_type index and metadata from catalog. Both were unused in Plone core and rarely used in addons. [jensens] (#3208)
• Plone 6 with markup update for Bootstrap. Extensive overhaul of Plone ui elements based on Bootstrap components. Introduction of icon resolver with use of icon_epr definitions. [1letter, agitator, ale-rt, balavec, ericof, erral, frapell, fredvd, fulv, gomez, jensens, krissik, mauritsvanrees, mrtango, nilshofer, petschki, santonelli, thet, thomasmassmann, tkimngyuen, tschorr] (#3249)

New features:

• Custom date format strings from registry can be in the ${} format as in the locales files. If there's a day or month name used, this will be translated. For bbb the classic strftime % strings are still behaving like before. [jensens] (#3084)
• Add icon resolver to return url or tag for given icon. [santonelli] (#3192)
• Include a controlpanel to inspect and rebuild relations. [pbauer] (#3231)
• Add PLONE60MARKER (and PLONE52MARKER) Python marker [sneridagh] (#3257)
• Protect @@historyview with Modify portal content permission. Fixes #3297 [pbauer] (#3297)

Bug Fixes:

• Add plone.app.caching to the list of add-ons that is upgraded when upgrading Plone. [maurits] (#82)
• Change control panel item sorting and sort them by title [erral] (#721)
• No longer doubly undo a response Content-Type change when combining bundles. [maurits] (#1924)
• Removed dependency on Products.Sessions. It is still pulled in by Products.PluggableAuthService though. See also CMFPlacefulWorkflow issue 35 <https://github.com/plone/Products.CMFPlacefulWorkflow/issues/35>_. [maurits] (#2957)
• Fix issue with @@search view when filtering by creation date [frapell] (#3007)
• Merge Hotfix20200121: isURLInPortal could be tricked into accepting malicious links. (#3021)
• Merge Hotfix20200121 Check of the strength of password could be skipped. (#3021)
• Improve tests for the workflow tool method listWFStatesByTitle (#3032)
• A default WSGI configuration requires Paste which is only installed with the Zope[wsgi] extra.. [tschorr] (#3039)
• Fixed deprecation warning for zope.site.hooks. [maurits] (#3130)
• Fixed use of own utils.isDefaultPage, which should be defaultpage.check_default_page_via_view. [maurits] (#3130)
• Fixed invalid escape sequences in regular expressions. [maurits] (#3130)
• PloneBatch: define __bool__ as copy of __nonzero__. Python 3 calls __bool__ when doing bool(batch). [maurits] (#3175)
• No longer consider calling len(batch) as deprecated. The deprecation warning is unvoidable with current Products.PageTemplates code. Fixes issue 3176 <https://github.com/plone/Products.CMFPlone/issues/3176>_. maurits (#3176)
• Fix tests with Products.MailHost 4.10. [maurits] (#3178)
• Applied: find . -name "*.py" |grep -v skins|xargs pyupgrade --py36-plus --py3-only. This auto-rewrites Python 2.7 specific syntax and code to Python 3.6+. [jensens] (#3185)
• Robot tests: Do not use jQuery.size() but use .length instead. .size() is deprecated since 1.8. [thet] (#3195)
• Remove traces of Archetypes [pbauer] (#3214)
• Fix problem to remove username and password from email settings if there was already one set. [jensens] (#3224)
• Fix migration when we have broken objects in the app root (e.g. the temp_folder) (#3245)
• Fixed tests in combination with Products.PluggableAuthService 2.6.0. [maurits] (#3251)
• Fix closing curly brace in search.pt template. [balavec] (#3252)
• Add the remote code execution fix from the Products.PloneHotfix20210518 expressions patch <https://plone.org/security/hotfix/20210518/remote-code-execution-via-traversal-in-expressions>_. We need this because Zope 4.6.2 is too strict for us. [maurits] (#3274)
• Removed the docstring from various methods to avoid making them available via a url. From the Products.PloneHotfix20210518 reflected XSS fix <https://plone.org/security/hotfix/20210518/reflected-xss-in-various-spots>_. [maurits] (#3274)
• Remove unused imports. [jensens] (#3299)
• Fix TypeError when adding a portlet. [daggelpop] (#3303)
• The portal catalog will not try to index itself anymore [ale-rt] (#3312)