Description:
I used to have this jcAnimCS script from CGToolKit for doing the usual copy and paste of keyframes from scene to scene. It worked fine until one day, an animator realized there were some keyframes didn't copy over. After looking into the codes, I realized the jcAnimCS script didn't consider any keyframes at subframes, i.e., frame 1.56. Most people wouldn't animate at subframes, however, that animator needed to scaled the entire animation down using graph editor which resulted in subframe keyframes. I have no way to ensure everyone not to do subframe animation, and therefore I rewrote a simpler version of copy and paste animation tool that allow subframes animation.

Installation:
Simply copy the downloaded Mel script to
C:\Documents and Settings\User\My Documents\maya\2008\scripts\
source the script from Maya Script Editor and run it by typing zinCopyAnim and hit enter key
Compatible to Maya 7.x .
Not tested on Linux

Usage:
1) Select the animated objects, hit Add Objects to List button. It will only add animated attributes into the list, and you could selectively removed any animated attributes you don't want to copy by selecting any item on the list and hit Remove selected from list button.

2) By Default, the animation data will save into the data folder of current project directory. Change it to anywhere you like.

3) Enter the filename with .txt extension.

4) Hit Copy Animation button and a window will prompt you when it is done.

5) To paste the animation, simply hit Select file to load animation button. Navigate to the locate the exported file and hit OK.
The animation should now be copied over.

6) The script is depending on searching the objects with the same names to its database. Therefore, renaming it would result in failing to copy animation.