[DOCS] Explain development model

Due to in2codes EAP program, it is necessary to explain the
current development model.

Documentation/DevelopmentModel.md

@@ -0,0 +1,56 @@
+# EAP, development and branching model
+
+## Early Access Program (EAP)
+
+The base for this development model is the **E**arly **A**ccess **P**rogram (EAP). The EAP provides a private, early
+access to a version of Powermail, which is compatible with the youngest TYPO3 LTS version. The reason for an EAP program
+is, that EXT:powermail and related extensions are considered feature complete and we need at least a partial
+re-financing of the development efforts.
+
+The code, developed while the EAP period, will become public nine months after the TYPO3 LTS was released. If you want
+to learn more about in2codes EAP program or have questions, please head over to
+[in2code EAP](https://www.in2code.de/en/agency/typo3-extensions/early-access-program/) or ask in the
+[#ext-powermail channel on TYPO3 slack](https://typo3.slack.com/archives/C06P2DQG2).
+
+
+## Which versions get which updates?
+
+| TYPO3 - compatibility | Support/Development | Example (TYPO3 version) | Branch name |
+|-------------------------------------------|-------------------------------------------------------------------------------|-----------------------------|----------------------|
+| upcoming TYPO3 LTS | Security, Bugfixes, Features, Breaking changes | v14 | master |
+| current TYPO3 LTS | Security, Bugfixes, Features, Breaking changes (until powermail release 13.0) | v13 (released October 2025) | master |
+| old TYPO3 LTS (before EAP becomes public) | Security, Bugfixes, Features | v12 (until July 2025) | typo3_v12 |
+| old TYPO3 LTS (after EAP becomes public) | Security, Bugfixes | v12 (after July 2025) | typo3_v12 |
+| TYPO3 ELTS | Security, Bugfixes (paid) | v11, v10, v09 | typo3_v11, typo3_v10 |
+
+## Branching Model
+
+The development for the youngest (or upcoming) TYPO3 LTS compatible version happens in branch `master`. Each older
+version has its own compatibility branch. The branch name has nothing to do with the powermail version.
+
+When the development for a recently published or upcoming TYPO3 LTS version starts a new branch for "LTS - 1" is
+created. For example, when the development for TYPO3 v13 compatibility starts, a new branch `typo3-v12` is created.
+At this moment this will be the default branch for the *public* repository "for the time being". The base of all open
+pull requests (against `master`) will be changed to the new branch by the maintainer.
+
+Development takes place in branches `docs`, `feature` and `bugfix`. Before merging they must meet following conditions:
+
+- necessary tests are added to the test suite
+- documentation is updated
+- branch is rebased onto the default branch
+- all tests are green: unit, acceptance, phpstan, codestyle
+
+If everything is fine, the branch is merged as fast forward. This ensures a nice history and makes it possible to have
+pretty releases at github with all solved issues and attributions to contributors.
+
+The development for public code takes place in the public repo. The private repository acts a mirror of these branches.
+
+The development for the upcoming compatibility release happens in branch `master` of the private repository. Branch
+`master` is blocked for everyone (even the maintainer) in the public repo until the EAP development becomes public
+(TYPO3 LTS release + 9 months).
+
+When the EAP phase is over, the code of branch `master` will be pushed as is to the public repo (including tags) and
+also available via packagist and the TYPO3 TER.
+
+
+

Documentation/Readme.md

@@ -38,7 +38,7 @@ Some basic points:
  (funnel, browser, language, country, etc...)
 
 - For Developers: Powermail is a very flexible extension, which also
- could be extended by your code or extension (hooks, eventdispatchers,
+ could be extended by your code or extension (hooks, events,
  own Finishers, own DataProcessors, own Spam-Prevention-Methods,
  own Validators, TypoScript cObjects and userFuncs, debugoutput, etc...).
 
@@ -87,6 +87,7 @@ See the reporting about the delivered mails (Form or Marketing Data Analyses are
 ## Documentation overview
 
 * [Introduction](/Documentation/Readme.md)
+* [Development Model](/Documentation/DevelopmentModel.md)
 * [Documentation for editors](/Documentation/ForEditors/Readme.md)
 * [Documentation for administrators](/Documentation/ForAdministrators/Readme.md)
 * [Documentation for developers](/Documentation/ForDevelopers/Readme.md)

Readme.md

@@ -1,11 +1,12 @@
 # TYPO3 Extension powermail
 
-Powermail is a well-known, editor-friendly, powerful
-and easy to use mailform extension for TYPO3 with a lots of features
-(spam prevention, marketing information, optin, ajax submit, diagram analysis, etc...)
+Powermail is a well-known, editor-friendly, powerful and easy to use mailform extension for TYPO3 with a lots of
+features (spam prevention, marketing information, optin, ajax submit, diagram analysis, etc...)
 
 > :warning: **TYPO3 13 compatibility**\
-> See [EAP page (DE)](https://www.in2code.de/agentur/typo3-extensions/early-access-programm/) or [EAP page (EN)](https://www.in2code.de/en/agency/typo3-extensions/early-access-program/) for more information how to get access to a TYPO3 13 version
+> See [EAP page (DE)](https://www.in2code.de/agentur/typo3-extensions/early-access-programm/) or
+> [EAP page (EN)](https://www.in2code.de/en/agency/typo3-extensions/early-access-program/) for more information how
+> to get access to a TYPO3 13 version
 
 ## :warning: Deprecations, planned breaking changes for V13 and features
 
@@ -35,6 +36,7 @@ throughout the last years and want to make available to the broader public, for
 ## 1. Documentation overview
 
 * [Introduction](/Documentation/Readme.md)
+* [Development Model](/Documentation/DevelopmentModel.md)
 * [Documentation for editors](/Documentation/ForEditors/Readme.md)
 * [Documentation for administrators](/Documentation/ForAdministrators/Readme.md)
 * [Documentation for developers](/Documentation/ForDevelopers/Readme.md)
@@ -58,18 +60,14 @@ Quick guide:
 
 | Powermail | TYPO3 | PHP | Support/Development |
 |-------------|-----------|-----------|------------------------------------------------|
+| 13.x | 13.x | 8.3 - 8.x | Features, Bugfixes, Security Updates |
 | 12.x | 12.x | 8.1 - 8.2 | Features, Bugfixes, Security Updates |
 | 11.x | 12.x | 8.1 - 8.2 | Support dropped |
-| 10.x | 11.x | 7.4 - 8.1 | Bugfixes, Security Updates   |
+| 10.x | 11.x | 7.4 - 8.1 | Security Updates (paid backports are possible) |
 | 9.x | 11.x | 7.4 | Support dropped |
 | 8.x | 10.x | 7.2 - 7.4 | Security Updates (paid backports are possible) |
-| 7.x | 8.7 - 9.x | 7.0 - 7.4 | Security Updates (paid backports are possible) |
+| 7.x | 8.7 - 9.x | 7.0 - 7.4 | Support dropped  |
 | 6.x | 8.7 - 9.x | 7.0 - 7.x | Support dropped |
-| 5.x | 8.7 - 9.x | 7.0 - 7.x | Support dropped |
-| 4.x | 7.6 - 8.7 | 5.5 - 7.2 | Security Updates (paid backports are possible) |
-| 3.x | 7.6 - 8.7 | 5.5 - 7.2 | Support dropped |
-| 2.18 - 2.25 | 6.2 - 7.6 | 5.5 - 7.0 | Support dropped |
-| 2.2 - 2.17 | 6.2 - 7.6 | 5.3 - 7.0 | Support dropped |
 
 Do you need free support? There is a kind TYPO3 community that could help you.
 You can ask questions at https://stackoverflow.com and tag your question with `TYPO3` and `Powermail`.