Houserules and Homebrews
http://www.mediafire.com/download/ebm5pnhmi9g67lg/Tyranid+Codex+v+2.1.pdf
Link to the newest Tyranid Fandex, includes updates based on the 6th edition codex.
I actually lost my old files in a crash, so this new one is based on parts reconstructed from the old pdf's. A lot of extra work, but I...