Finding plugins which I can use for theme development

Hello,

It’s a little bit hard for me to find out which plugins I can use for premium theme development a d which I can’t.

Actually, I’m looking for a slider, which I can use for free (On the web page of Flexslider I can’t find License Information, for example). But in the future I might also be looking for other plugins which I can’t use and on the standard plugins page I often can’t find information about if I can use it for a premium theme or not.

Do you know a list of plugins, I can use for free?

thank you

thank you.

I can use all these plugins for premium themes? so also the nivo slider (http://wordpress.org/extend/plugins/wp-nivo-slider/developers/)? Because on dev7studios it costs money

pretty sure those aren’t the same plugins 1 the one on the nivo site is actually a different version number(1.7) and the other is that to even be accepted in the codex is that it has to be GPL

ok, so I can use files with the GNU General Public License and also the MIT License, right?