Upgrading 5.3 to 6.0 question

[Michael S]

Good day all.

I have a question related to upgrading my machine from 5.3 to 6.0.
I am convinced I need to upgrade it, and the base system upgrade
procedure is pretty much clear to me. However I am somewhat not clear
about 3rd party software. Since all the programs are 5.X binaries, do
I need to recompile/reinstall all of them? Or they can run fine under
COMPAT_FREEBSD5?

Thanks in advance.
Michael