Juku, which we covered when it went on the market, let users write up to 140-character messages which showed up on a page along with similar messages from Windows Live Messenger contacts. A competitor, Plurk, pointed out that Juku’s code and appearance had a very striking resemblance to its own (See screenshots below). In a blog post, it said it was “in shock asking why Microsoft would even stoop to this level of wilfully plagiarising a young and innovative upstart’s work rather than reach out to us or innovate on their own terms.”

The charge has to be especially hard for Microsoft to take, considering the company’s many efforts to protect its own intellectual property in China, where a staggering 82 percent of software on the market was unlicensed last year, according to the Business Software Alliance.

Here’s a screenshot of Microsoft’s Juku:

And here’s Plurk:

Update: And Microsoft now says in a new statement that, as commenters below suggested, Juku was developed by a Chinese vendor, who the company says has admitted to copying the code. Microsoft is now suspending access to Juku “indefinitely.”