Application Updates for Leopard?

I have downloaded and collected many programs for Tiger and am curious if they will run when I upgrade to Leopard - Will I have to download updates or, patches?

Some will run fine out of the box, lots will need a patch to run smoothly.

For that reason some people like to wait a month or two before installing a major new OS: That gives the app makers time to update their software.

In my company for instance though, our aim is to have all current software Leopard compatible from day 1 - in some cases even the previous version of the software as well.

edit i couldnt find delete

Thanks Aptmunich, I think the only issue I will have then is the freeware programs, with updates that is, all the others are produced by some big gun companies.