Well I've noticed several people trying to login an getting errors so am gonna repost the guide for my server since whoever keeps trying to login is trying to do so from a vanilla client.
First off since its a tekkit server you will need to download the technic launcher:
Launcher download
This will install separate to you're vanilla client so it wont affect it at all.
Once downloaded when you launch it in the top left corner you can select from several different mod packs for my server select
Tekkit.
After you have it set to tekkit at the bottom right corner open the options menu an click manually select build an in the drop down box select
3.0.3| 1.2.5| Rec. Build. Once that's done you're ready to login it will start patching to the correct build from this point login to the server with the IP below.Also in the option's menu you can select how much ram to allow minecraft to use which if you bump it to 2+ GB's it should eliminate crashes do to lack of memory as by default minecraft only uses 1gb of ram.
For some people when they login after freshly patching the client the map wont load first time you login if this happens just restart the client an you will be good to go it shouldn't happen again.
Server IP: 67.85.67.78
If you're looking for info on any of the mods in the modpack this page:
Tekkit At the bottom it lists the mods with links to the authors pages where you can find all the info on each mod as well as links to wiki's the authors have set up.