Merge pull request leereilly#465 from Aristarhys/master

Fix typo and add System Shock entry

Author: leereilly

README.md

@@ -397,7 +397,7 @@ A selection of major game studios, publishers, etc. using GitHub:
 * [MegaGlest](https://github.com/MegaGlest/megaglest-source) - MegaGlest real-time strategy game engine (cross-platform, 3-d).
 * [Micropolis](https://github.com/SimHacker/micropolis) - City-building game based on the original code for SimCity.
 * [openage](https://github.com/SFTtech/openage) - Clone of the Age of Empires II engine.
-* [OpenDungeons] (https://github.com/OpenDungeons/OpenDungeons) - Open source game inspired by Dungeon Keeper - Dark, damp and dangerous...
+* [OpenDungeons](https://github.com/OpenDungeons/OpenDungeons) - Open source game inspired by Dungeon Keeper - Dark, damp and dangerous...
 * [OpenFodder](https://github.com/OpenFodder/openfodder) - Open-source implementation of Cannon Fodder
 * [OpenRA](https://github.com/OpenRA/OpenRA) - Open-source implementation of the Red Alert engine using .NET/mono and OpenGL. Runs on Windows, Linux and OSX.
 * [OpenTTD](https://github.com/OpenTTD/OpenTTD) - OpenTTD is a transport simulation game based upon the popular game Transport Tycoon Deluxe, written by Chris Sawyer.
@@ -474,6 +474,7 @@ A selection of major game studios, publishers, etc. using GitHub:
 * [OpenJK](https://github.com/JACoders/OpenJK) - Community maintained fork of Jedi Academy and Jedi Outcast development.
 * [Prince of Persia](https://github.com/jmechner/Prince-of-Persia-Apple-II) - Source code for the original Prince of Persia game that was written on the Apple II, in 6502 assembly language, between 1985-89.
 * [UFO RUN](https://github.com/Nextpeer/Nextpeer-UFORUN) - Real time multiplayer with Nextpeer.
+* [System Shock](https://github.com/NightDiveStudios/shockmac/) - Source code for original System Shock game (PowerMac version), more readable fork available [here](https://github.com/ToxicFrog/shockmac).
 
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