There are a lot of Multisite plugins out there to display which plugins are active where on a Multisite install. Unfortunately none of them seem to display the data in a really usable format at large scale. However, one thing that does handle large data well is spreadsheets.
This plugin takes a list of all available plugins on the site and outputs which plugins are active on which sites. It also breaks out how the plugin is activated. This is good for cases where you activated a plugin on certain sites then went back and network activated it.
Once you’ve generated a spreadsheet of the plugins from your network, feel free to open it and sort or filter columns to find out exactly where a specific plugin is activated. It’s certainly made reporting easier on our end.
Across the top is a column for every plugin available on the network. It shows both the plugin name (as specified in the plugin file), as well as the plugin file path so that you can track it down.
Below that is a row for every site in your Multisite network. This will show you if the plugin is activated manually (on a specific site), if it’s network activated, or if it’s not activated at all.
The plugin can be found on Github at https://github.com/maintainn/multisite-plugin-theme-csv
Try it out and let us know what you think!
Update April 7th, 2014: I’ve added the ability to do this for themes as well. As such, the GitHub repository name and link in this article have been updated to reflect this change. More information can be found over on GitHub.