Microsoft released an update to its Silverlight media streaming client that fixes a range of bugs in both the Windows and Mac OS versions.

Instead of a patch, per se, Microsoft (NASDAQ: MSFT) released an update to Silverlight on Thursday. Most Silverlight users will be offered the update via the Silverlight installer, but there are other delivery options, as well.

"If your computer does not have Silverlight installed, the installer will be offered to you by Microsoft Update or by Windows Server Update Services (WSUS)," a knowledge base article posted to Microsoft Support online said.

WSUS is designed to simplify software distribution inside the corporate firewall.

Silverlight is a multi-platform, cross-browser streaming media technology that runs on both Windows and Mac OS with Internet Explorer (IE), Mozilla Firefox, and Apple Safari browsers. Microsoft introduced Silverlight in April 2007 as a competitor to Adobe Flash.

Since then, Silverlight's fortunes have alternately risen and fallen, though market share has continued to grow. Microsoft has hung in, releasing multiple versions. Most recently, the company shipped Silverlight 4.0 in April.

The new -- updated -- version is numbered Silverlight 4 (4.0.50524.0).

The bugs that the updated Silverlight 4 release fixes include one where if a user types a random string at the end of a Web request, it causes the Silverlight application to crash.

Two other bugs fixed in the update are related to use of Microsoft's PlayReady digital rights management (DRM) technology. Without the update, PlayReady-encrypted media will not play on "certain configurations" of Windows XP or Mac OS, according to the article.

Also among the bugs fixed by the update is one that, when a Silverlight 4 plug-in is used with a Mac browser, creates a large memory leak when playing back a long media stream.

The latest update to Silverlight is available here.

Stuart J. Johnston is a contributing writer at, the news service of, the network for technology professionals.