Snapshot are not built automatically any more. Use the CA Downloader to download CA.

Or download a stable release from http://files.caspring.org/snapshots/.

What are all those files?

ca-r*.sdz
Complete Annihilation main mod archive. This is sufficient to play.
ca-aa211-r*.sdz and ca-aa146-r*.sdz
Mutators that turn CA into AA 2.11 or AA 1.46 while keeping the new effects and models. Both require the main mod archive and AA 1.46 for CA requires AA 2.11 for CA.
ca-deployment-r*.sdz
Mutator for Complete Annihilation that adds trepan's LuaRules Deployment: you can place your units and give orders to them before the game starts. Requires the main mod archive.
ca-tactics-r*.sdz
Same as above, except builders, factories and turrets are disabled. Requires the main mod archive.
ca-sli-r*.sdz
Balanced Annihilation mutator for CA, with some other changes. Requires the main mod archive.
docs
Contains various licenses covering CA content as well as this readme.
ca-all-r*.zip
Collection of all of the above for convenient download.