The bundle contains clustalx and clustalw binaries. To run clustalx, you should have installed XDarwin, and lesstiff (needed by ncbi vibrant toolkit).
To use clustalx, you should run XDarwin first.
gunzip clustal_mac_x.tar.gz tar clustal_mac_x.tar
Now download clustal-mac-x.tar.gz
Chenna Ramu