Is ext3cow still being developed?

Title say's it al开发者_JAVA百科l, Just wondering if ext3cow is still being developed?

Not it's not maintained anymore. It went off the radar screen in 2008 and so did the tools (only the hg source code repo seems to be available). but that was a separate initiative anyway. The lead developer Zachary Peterson seems to have shifted its interest to other matters.
From Tim Post's (the developer of the tools) own admission:

Note, there are several minor bugs that I never fixed, mostly because ext3cow more or less died off. If you find a bug, let me know, I’ll fix it.

You may want to ask here, ext3cow-devel@hssl.cs.jhu.edu

Zachary posted there in March 2009, although that was one of the last updates to the list...

According to his web page, he's still a "lead developer",

http://hssl.cs.jhu.edu/~zachary/www/home.html