Free approval workflow engine software for linux

PHP Tag Engine project is a library that allows you to easily add tagging functionality to a PHP application.
Main features:
- PHP Tag Engine has a full AJAX front-end for tagging, as well as methods for programatically adding tags in your code. The front-end tagging interface even has auto-complete functionality using the excellent Yahoo! Auto-Complete library.
- A built-in cache to reduce database queries.
- The PHP Tag Engine code is fully documented in PHP Doc format, and PHP Doc generated documentation is available for download.
- Fully internationalized including Javascript strings. English localization included.

Absolut Engine is a news publishing system. It features three-layer access (admin/chief/editor), article posting, editing, and deleting. Absolut Engine includes a powerful image managing tool, a file manager, and a related articles manager.

Rich text editing is provided via a built-in WYSIWYG editor that produces XHTML 1.0 Strict-compliant code. Absolut Engine is easy to extend via module functionality. The provided modules include Discussions, Surveys, RSS Feed, Search Engine Optimization (static/clean URLs), and a message system for better communication between users.

Absolut Engine produces Web-standards-compliant valid and accessible XHTML 1.0 Strict and CSS semantically-correct code.

The Irrlicht Engine is an open source high performance realtime 3D engine written and usable in C++ and also available for .NET languages.
Irrlicht Engine is completely cross-platform, using D3D, OpenGL and its own software renderer, and has all of the state-of-the-art features which can be found in commercial 3d engines.
Weve got a huge active community, and there are lots of projects in development that use the engine.
You can find enhancements for Irrlicht all over the web, like alternative terrain renderers, portal renderers, exporters, world layers, tutorials, editors, language bindings for java, perl, ruby, basic, python, lua, and so on. And best of all: Its completely free.
Main features:
- High performance realtime 3D rendering using Direct3D and OpenGL [more]
- Platform independent. Runs on Windows95, 98, NT, 2000, XP and Linux.[more]
- Huge built-in and extensible material library with vertex and pixel shader support [more].
- Seamless indoor and outdoor mixing through highly customizeable scene mangagment. [more]
- Character animation system with skeletal and morph target animation. [more]
- Particle effects, billboards, light maps, environment mapping, stencil buffer shadows, and lots of other special effects. [more]
- .NET language binding which makes the engine available to all .NET languages like C#, VisualBasic, and Delphi.NET.
- Platform and driver independent fast software renderer included. It features z-buffer, gouraud shading, alpha-blending and transparency, fast 2D drawing.
- Powerful, customizeable and easy to use 2D GUI System with Buttons, Lists, Edit boxes, ..
- 2D drawing functions like alpha blending, color key based blitting, font drawing and mixing 3D with 2D graphics.
- Clean, easy to understand and well documentated API with lots of examples and tutorials.
- Written in pure C++ and totally object orientated.
- Direct import of common mesh file formats: Maya (.obj), 3DStudio (.3ds), COLLADA (.dae), DeleD (.dmf), Milkshape (.ms3d), Quake 3 levels (.bsp), Quake2 models (.md2), Microsoft DirectX (.X)... [more]
- Direct import of Textures: Windows Bitmap (.bmp), Portable Network Graphics (.png), Adobe Photoshop (.psd), JPEG File Interchange Format (.jpg), Truevision Targa (.tga), ZSoft Painbrush (.pcx)... [more]
- Fast and easy collision detection and response.
- Optimized fast 3D math and container template libraries.
- Directly reading from (compressed) archives. (.zip)
- Integrated fast XML parser.
- Unicode support for easy localisation.
- Works with Microsofts VisualStudio6.0?, VisualStudio.NET 7.0-8.0?, Metrowerks Codewarrior, and Bloodshed Dev-C++ with g++3.2-4.0.
- The engine is open source and totally free. You can debug it, fix bugs and even change things you do not like. And you do not have to publish your changes: The engine is licensed under the zlib licence, not the GPL or the LGPL.

KoalaMud Game Engine project is a multithreaded MUD server.
KoalaMud is a MUD source base designed around multithreading and stability. On top of this platform, Shadow of the Wheel is evolving to demonstrate its capabilities.
Enhancements:
- Tons of new stuff done here.
- We now have basic rooms support completed, though there are still some additional pieces to be flushed out.
- We also have the first part of the skills system outlined and language support is more flushed out now.
- The network code has been completely rewriten to extract Qt from that loop.
- All input is now processed in the thread pool via ZThread tasks.
- Overall the system seems to be even more responsive now and I have not had nearly as many problems with stability since this code conversion.
- Split commands into multiple command trees that are searched as needed.
- Currently we have standard commands and immortal commands.
- All of the OLC editors have been moved under the olc command tree for simplicity and consistancy as well.
- This also paves the way for aliases later on.
- Also added color marker support.

madlibs engine project is a MadLibs clone.

The madlibs engine is a tiny engine for MadLibs-like interactive stories. Basically, you enter different words of a certain part of speech.

The program pastes them into a story text, creating weird, funny, or stupid results.

It runs on anything from a line printer to an xterm.

poker-engine is a C library to evaluate poker hands. The result of the evalution for a given hand is a number. The general idea is that if the evalution of your hand is lower than the evaluation of the hand of your opponent, you lose.
Many poker variants are supported (draw, holdem, omaha, etc.) and more can be added. poker-eval is designed for speed so that it can be used within poker simulation software using either exhaustive exploration or Monte Carlo.
Enhancements:
- Implementation of tournament breaks and bugfixes.

Kyra Sprite Engine project is a C++ sprite engine built on SDL.
Kyra is a simple, fully featured Sprite engine written in C++. The Kyra engine is suited to 2D, isometric, and quasi-3D games.
It is built on top of SDL for cross platform use. It supports tiles, sprites, and user drawn surfaces.
It has full support for alpha blending, scaling, color transformation, pixel perfect collision detection, OpenGL acceleration, and mouse testing.
It comes with tools to define sprites and import images into the system.
Enhancements:
- Update Kyra to work with the new SDL 1.2.11
- Fixed 64 bit support for Kyra.