I’m in the process of developing a plugin, and I’d like to figure out which versions of WordPress to support. But to get a good idea I’d need to know what percentages of old WordPress versions make up the install base. Does such information exist?
Alternatively if such information doesn’t exist, does anyone have a suggested version I should support my plugin back to?
There’s a page in the Codex that shows exactly that:
But really, it all depends on what features you’re using. A safe bet for a new plugin would be to support WordPress 3.1.X and above (since that’s the current stable release). You’re setting yourself up for a lot of hurt if you try to do too much backwards compatibility work.
WordPress.org publishes the aggregate installation stats collected by api.wordpress.org.