Is It Illegal To Use Invision Power Board V1.3? :huh:

If you didn't download it from us years ago when it was available, then no. It is illegal to download it from a third party and install it.

That is setting aside the fact that it is no longer supported, and there are numerous security holes present in it, and it doesn't support PHP 5 nor MySQL 5, among other limiting factors.

So if i downloaded it long time ago i can use it?

http://forums.invisionize.com/index.php?showtopic=97385
http://forums.invisionize.com/index.php?showtopic=99250

those 2 add-ons for IPB 1.3.0 Final make it PHP 5 computable and also adds all security

Or you could just buy a license and get the actual supported software with no questionable third-party security fixes in it. You get what you pay for.