Suffix aliases are supported in zsh since version 4.2.0. Some examples:
alias -s tex=vim
alias -s html=w3m
alias -s org=w3m
Now pressing return-key after entering foobar.tex starts vim with foobar.tex. Calling a html-file runs browser w3m. www.zsh.org and pressing enter starts w3m with argument www.zsh.org.
