what's the best bb for frequent updates, many functions, many mods, and many skins? (must be free)

I'd say phpBB. There are hundreds of mods, hundreds of skins, it's got a fair amount of features. Whilst they're not updating it with any more features at the moment, there is development with phpBB 3, which could rival Invision with its features.

Others might say myBB or punBB so you can have a look at them as well and see which one you like best.

heard phpbb has many security holes

It has had its fair share of security issues lately, but I see no reason to be worried if you're running the latest version.

Did you have a look at myBB and PunBB?

MyTopix

phpBB

IPB 1.3 due to PHPBB is very vunerable, has security holes and basically your just asking for an easy hack.

-DannyGlass

not true...

In the last 2 months they've released 3 updates with fixes for security exploits(more than one for each update).
http://www.phpbb.com/phpBB/viewtopic.php?t=265423
http://www.phpbb.com/phpBB/viewtopic.php?t=267563
http://www.phpbb.com/phpBB/viewtopic.php?t=281963

First he said it must be free. And as far as security holes, I've been using phpbb for a while now and as long as the fixes are applied you shouldn't have any problems. Add the release of fixes just shows they doing some work on it. Look how many vulnerabilities come out for Windows and how long they take to fix. There are also security mods that will help. As far as mods and stuff go, we've been using Plus 1.52 for phpbb2. It has a ton of mods included, but there aren't near as many themese for it because of all the mods. I have not used the others but will say the phpbb is easy to set up and I haven't had any problems with security myself.

I would say either myTopix or myBB!

vb

phpBB simple, free, and EASY to customise

Please learn to read. Also, vB?

mybb

www.mybboard.com