Halo 1 in particular has many community-made tools which complement or replace functions of the official mod tools. It's not usually necessary for beginners to to use them, but they can unlock advanced workflows or save time.
General tips
Some golden rules for using community-made tools are:
- Read the
README.txtor other available documentation. It will often answer your setup or usage questions. - Keep it updated! Actively maintained projects release bug fixes and new features. A problem you're having might be fixed in the current version.
Categories
Community tools/mods usually fall into these categories.
Game client mods
These are mods which change the game client itself, like adding features or fixing bugs. Popular examples for Custom Edition include Chimera, HAC2, and OpenSauce. MCC does not have widely used client mods.
Mods like this are usually built as DLLs which load with the game and perform runtime modification of game memory and code. For this reason they aren't usually compatible with each other, since they would interfere and cause crashes.
Toolsets
Projects which aim to replace or improve upon functions of the official modding tools include invader, MEK, and OpenSauce. They may extend modding capabilities or offer new workflows.
3D creation plugins
The cross-game Halo Asset Blender Development Toolset is an essential add-on for Blender and covers most needs for importing and exporting 3D assets. It's usually preferable to the FBX pipeline.
Plugins for 3ds Max are all old and unmaintained at this time: