I'm going to try and make a definitive list of the source ports out there for GOG games. Post ones you know about!! :)

(In alphabetical order.)

___________
Baldur's Gate
-------------------
GemRB - Engine Remake

________________
Beneath a Steel Sky
----------------------------
ScummVM

_____
Blood
---------
Blood32
BloodTC
Hypertension
OpenBlud
Transfusion TC
ZBlood TC

______
Blood 2
----------
Blood 2 Resurrection

_______________
Broken Sword 1 & 2
---------------------------
ScummVM

____________
Call to Power 2
---------------------
Call to Power 2 Source Code Project

___________
Descent 1 & 2
--------------------
D2X-XL
DXX-Rebirth

_____________
Duke Nukem 3D
----------------------
Duke3d_w32
Duke3dw
EDuke
GlDuke3d
JFDuke3D
LDuke3d
OpenDuke

______
Far Cry
----------
FCAM - FarCry Addon Mod

_____________
The Feeble Files
-----------------------
ScummVM

__________
Freespace 2
------------------
FSOpen

___________
Gabriel Knight
--------------------
ScummVM SVN - Not finished yet, playable in SVN

_____________
Gobliiins Series
----------------------
ScummVM

_________________________
Heroes of the Might and Magic 2
--------------------------------------------
Free Heroes II Project - Engine Remake

_________________________
Heroes of the Might and Magic 3
--------------------------------------------
VCMI Project - Engine Remake

__________
Icewind Dale
------------------
GemRB - Engine Remake

______________
Jagged Alliance 2
------------------------
JA2 1.13
JA2 Stracciatella

__________
King's Quest
-----------------
ScummVM SVN

__________________
Lure of the Temptress
------------------------------
ScummVM

____
Myst
-------
ScummVM SVN - Not finished yet, playable in SVN

________________
Personal Nightmare
----------------------------
ScummVM SVN - Not finished yet, playable in SVN

_____________
Phantasmagoria
-----------------------
ScummVM SVN - Not finished yet, playable in SVN

________________
Planscape: Torment
----------------------------
GemRB - Engine Remake

_____________
Red Baron Pack
-----------------------
Red Baron 3D

________________
Redneck Rampage
---------------------------
eRampage

_____________
Rise of the Triad
----------------------
Rise of the Triad for Linux (and Win32, and OSX, and even DreamCast!)
WinROTT & WinROTTGL

____
Riven
--------
ScummVM SVN

________
Sanitarium - Not playable since it is not finished yet
--------------
Asylum Engine
ScummVM

__________________
Seven Kingdoms 1 & 2
--------------------------------
Seven Kingdoms Source Code Project - SK2 only has source code repository, no work on it has started yet

________________________________
Simon the Sorcerer 1 & 2 + Puzzle Packs
-------------------------------------------------------
ScummVM

__________
Space Quest
------------------
ScummVM SVN

________
Teenagent
---------------
ScummVM

____________________
Temple of Elemental Evil
----------------------------------
TOEE Engine Recreation Project - Engine Remake

______________
Total Annihilation
------------------------
Spring Engine - Engine Remake
TA3D - Engine Remake

__________
Tyrian 2000
----------------
Open Tyrian

_____
Unreal
---------
Old Unreal
Unreal Direct3D 10

_______________
Unreal Tournament
--------------------------
Unreal Tournament Direct3D 10
UTGLR

________
Waxworks
--------------
ScummVM




Please post any others that you are aware of! :)

Don't forget Eduke for Duke Nukem 3D, and Doom isn't a gOg game at present.

*Updated


And yeah, I was actually thinking Duke Nukem...for some reason I put Doom, lol!

All of these may not have source code but are engine replacements nonetheless. Not all of them are finished either (SCP = Source Code Project)

Heroes of the Might and Magic II:
Free Heroes II Project - Engine Remake

Heroes of the Might and Magic III:
VCMI Project - Engine Remake

Total Annihilation:
Spring Engine - Engine Remake
TA3D - Engine Remake

Jagged Alliance 2
JA2 1.13 - SCP
JA2 Stracciatella - SCP

Infinity Engine Games (Planescape, Icewind Dale & Baldur's Gate)
GemRB - Engine Remake

Temple of Elemental Evil
TOEE Engine Recreation Project - Engine Remake

Call to Power II
Call to Power II Source Code Project - SCP

Seven Kingdoms 1 & 2
Seven Kingdoms Source Code Project - SCP (SK2 only has source code repository, no work on it has started yet)

*Updated

These are the ones i know about, source ports and TCs, just FPS though, thanks for the rest of the source ports, wish there was one for Commandos. Also added (not really source ports but anyway) Sanitarium, MYST/MYST ME and Riven. Lure of the Temptress, Beneath a Steel Sky, Teenagent, Gabriel Knight, King's Quest, Phantasmagoria, Space Quest.

Beneath a Steel Sky:
ScummVM

Blood:
Transfusion TC
OpenBlud
Hypertension
ZBlood TC
Blood32
BloodTC

Blood 2:
Blood 2 Resurrection

Descent 1:
DXX-Rebirth
D2X-XL

Descent 2:
DXX-Rebirth
D2X-XL

Duke Nukem 3D:
eDuke32
Duke3dw
JFDuke3D
Duke3d_w32
GlDuke3d
LDuke3d
OpenDuke

Far Cry:
FCAM (FarCry Addon Mod)

Gabriel Knight (not finished yet, playable in SVN):
ScummVM SVN

King's Quest:
ScummVM SVN

Lure of the Temptress:
ScummVM

MYST/MYST ME (not finished yet, playable in SVN):
ScummVM SVN build

Phantasmagoria (not finished yet, playable in SVN:
ScummVM SVN

Redneck Rampage:
eRampage

Rise of the Triad:
WinROTT & WinROTTGL
Rise of the Triad for Linux (and Win32, and OSX, and even DreamCast!)

Riven (game is playable and completable in SVN):
ScummVM SVN

Sanitarium (not playable since it is not finished yet):
ScummVM
asylumengine

Space Quest:
ScummVM SVN

Teenagent:
ScummVM

Unreal:
Unreal Direct3D 10
Old Unreal

Unreal Tournament:
UTGLR
Unreal Tournament Direct3D 10


Edit: Added Sanitarium plus MYST/MYST ME (support not finished yet), Riven. Lure of the Temptress, Beneath a Steel Sky, Teenagent, Gabriel Knight, King's Quest, Phantasmagoria, Space Quest.

*Updated

Some others i forgot the first time around:

Broken Sword 1 & 2:
ScummVM

Gobliiins series:
ScummVM

Personal Nightmare (not finished yet, playable in SVN):
ScummVM SVN build

Simon the Sorcerer 1 & 2 plus puzzle packs:
ScummVM

The Feeble Files:
ScummVM

Waxworks:
ScummVM

Edit: You can play Descent 1 on D2X-XL too so you might want to add that one to the list as well ;-)

Thank you very much Spinvis and Petrell!!

*Updated

Bump - for great justice.

GemRB also, of course, supports the sequels to the already mentioned games. Icewind Dale 2 and Planescape: Torment are not yet completeable though.

I haven't tried it yet but I think it belongs here

Freespace 2
http://www.fsoinstaller.com/index.html

Freespace 2 is already on the list ;) - and the source code project is excellent.

However, I'm not sure that Red Baron 3D counts as a "source port" - at least not in the same way as many of the others are - Red Baron 3D wasn't an open source project. While it did change the engine, Red Baron 3D was the official "superpatch" to Red Baron II by Sierra which was also sold as its own game to those who had never bought Red Baron II. Most of the current things out there for it are mods and toolshed upgrades, but nothing that have changed the source code since then. I have heard rumors of a planned source code project for it though ...

Thanks very much for the effort, A_Future_Pilot. Well well... I can only say I love source ports, cause they preserve the game or enhance it even further.

HeXen 2:
Ultimate Quake Engine (shortened as UQE, funny that it only supports HeXen 2 as of now)

Operation Flashpoint: (more like mods, changing it to be more realistic plus fixes, like the FCAM mod for Far Cry you posted)
ECP Redux 1.1
WGL 5.1 (WarGames League 5.1)
FFUR 1985 1.05

Blood:
Once I've made a post about Blood, here.

There's also the Commander Keen and other links I've posted, all scattered in this thread., hundreds of posts.

Help add these ports to their game's pages on the GOGWiki!