+ Castle Engine, TileEngine, SDL2, SFML (from PR #44, I believe I extracted all new items from it).

+ More additions to contributing rules

README.md

@@ -166,7 +166,15 @@ This awesome collection is also available on [Delphi.ZEEF.com](https://delphi.ze
 
 * [CrystalPathFinding](https://github.com/d-mozulyov/CrystalPathFinding). Simple and effective library with an open source intended for the searching of the shortest paths by algorithms A*/WA* for maps based on tiles with 4 (simple), 8 (diagonal/diagonalex) or 6 (hexagonal) neighbors.
 
-* [Allegro-Pas](https://sourceforge.net/projects/allegro-pas) ([GitHub](https://github.com/niuniomartinez/allegro-pas)). Wrapper to use the Allegro game librery with Pascal/Delphi.
+* [Allegro-Pas](https://sourceforge.net/projects/allegro-pas) ([GitHub](https://github.com/niuniomartinez/allegro-pas)). Wrapper to use the Allegro game library with Pascal/Delphi.
+
+* [Castle Engine](https://github.com/castle-engine/castle-engine). Complete Pascal Game Engine. Cross-platform 3D and 2D game engine with a lot of graphic effects and a scene graph based on X3D.
+
+* [TileEngine](https://github.com/megamarc/Tilengine). Wrapper to use the Tilengine game library with Pascal/Delphi. Tilengine is a cross-platform 2D graphics engine for creating classic/retro games with tilemaps, sprites and palettes. Its scanline-based rendering algorithm makes raster effects a core feature, a technique used by many games running on real 2D graphics chips.
+
+* [SDL2](http://www.freepascal-meets-sdl.net/) ([GitHub](https://github.com/ev1313/Pascal-SDL-2-Headers)). Pascal SDL 2 Headers. Simple DirectMedia Layer is a cross-platform development library designed to provide low level access to audio, keyboard, mouse, joystick, and graphics hardware via OpenGL and Direct3D.
+
+* [SFML](https://github.com/CWBudde/PasSFML). Pascal SFML Headers. SFML provides a simple interface to the various components of your PC, to ease the development of games and multimedia applications. It is composed of five modules: system, window, graphics, audio and network. Currently Delphi and FPC/Lazarus are supported. However, due to a compiler incompatibility with the Delphi compiler (solved with workarounds), FPC is recommended at the moment.
 
 
 ## Communications ##
@@ -705,6 +713,8 @@ This awesome collection is also available on [Delphi.ZEEF.com](https://delphi.ze
 * [Browse and Doc It](http://www.davidghoyle.co.uk/WordPress/?page_id=872). Plug-in allows you to document and browse your code from within the IDE.
 
 * [Integrated Testing Helper](http://www.davidghoyle.co.uk/WordPress/?page_id=874). Plugin for Delphi and RAD Studio that allows you to run command-line application before and after the compilation of you projects. It also provides the ability to zip you projects files into an archive on each compile/build and manage the application's version information.
+
+
 ## Documentation ##
 
 * [SynProject](https://github.com/synopse/SynProject) ([docs](http://synopse.info/fossil/wiki?name=SynProject)). Tool for code source versioning and automated documentation of Delphi projects.

contributing.md

@@ -6,10 +6,14 @@ Please ensure your pull request adheres to the following guidelines:
 - Search previous suggestions before making a new one, as yours may be a duplicate.
 - Make sure your suggestion is useful before submitting. That implies it having enough content and every item a good succinct description.
 - Make an individual pull request for each suggestion.
-- Use the following format: `[Title](link). Short author description` where `Short author description` strictly starts from a definition of a project. No **articles** or **project name repetitions** is allowed!
-	- Good: `[Hello world](example.com). Classic minimal project.`
-	- Bad: `[Hello world](example.com). A classic minimal project.`
-	- Bad: `[Hello world](example.com). Hello world is classic minimal project.`
+- Use the following format: `[Title](link). Short author description <LineBreak> // *Your short comment*` where:
+	- `Title` is the official name of a project
+	- `link` points to source repository or, *if absent*, any info/download page. If you feel necessary to add a link to some site and a repository info doesn't point to it (no README or whatever), you can add link(s) after the main one: `[Title](link) ([Docs](example.com), [Active fork](example.com), etc).`
+	- `Short author description` strictly starts from a definition of a project. No **articles** or **project name repetitions** is allowed!
+		- :white_check_mark: Good: `[Hello world](example.com). Classic minimal project.`
+		- :x: Bad: `[Hello world](example.com). A classic minimal project.`
+		- :x: Bad: `[Hello world](example.com). Hello world is classic minimal project.`
+	- `Your short comment` (*optional*) is a really short comment that you're sure will be useful for others
 - Link additions should be added to the bottom of the relevant category.
 - New categories or improvements to the existing categorization are welcome. In most cases, new category should go **before** `Unit Testing` category as the end of the list is dedicated for developer tools and then various utilities.
 - Check your spelling and grammar.