I've integrated Wei Zhuo's Image Manager plugin as a patch for FCKeditor. Is quite similar to the iManager plugin but a bit simpler in features & user interface, IMO offering the most necessary features to a user.
Check out a demo of the htmlarea plugin version at http://www.zhuo.org/htmlarea/.
I have uploaded this as a patch at: https://sourceforge.net/tracker/index.p ... tid=543655
New Plugin: Image Manager from Wei Zhuo