The only allowable Mods to date are Optifine & Shaders. Any other mods you wish to see allowed on the server can be posted here for review and approval.
Resources texture packs are also allowed, except for Xray resource packs. If you are not sure if your texture is allowed submit it here for review and approval.
As stated in the FAQ
Can I use Optifine, Shaders or Resource Packs? – Yup, just make sure that you dont use X-Ray Resource Packs.
Any mod that gives you an advantage over other players are not allowed and will result in a ban.
This list will be updated upon admin approval of new mods.