I noticed recently that some people on Halopc.net are remaking Marathon into Halo CE. The following posts were by thinkreddie at Halopc.net.
First Post:
I read a topic on the bungie forums requesting a remake of Marathon.
Finally, an idea for a Halo project came to me. Remaking Marathon as a series of Halo CE maps would be beyond awesome.

So, I've decided to try and recruit a team for the job.
We'll need:
1- A modeler, to create biped models, scenery, weapons, and BSPs.
2- A Model Rigger, to rig the models for animation.
3- An animator, to animate bipeds and third/first-person views of the weapons.
4- A skinner, to skin the weapons/bipeds/level mesh.
5- Somebody who is experienced in UVW mapping.
6- Somebody who can tag all of the custom content.
7- Somebody who can populate and build the levels.
8- An uber scripting specialist.
9- A sound person who can comile dialogs, sound effects, and background sounds.

I may have missed some, let me know if I did.
Anybody interested? I can probably take on number 6 or 7.

EDIT: I forgot about sounds. Yes, we'll need somebody to make some sound tags.

Second Post:
Here's the roster so far:
1- Matooba, Evil_Monkey
2- Matooba
3- Matooba
4- Sgt Botley???
5- Sgt Botley???
6- thinkreddie, ledhedgn???
7- thinkreddie, ledhedgn???
8- (nobody yet...)
9- (nobody yet...)

We need more!
Well, thought I might as well make Modacity aware of this project.
Edit: Almost forgot the original URL
http://halopc.moddercentral.net/halo...er=asc&start=0