Microsoft made an unspecified investment in Move Networks, a company that supplies streaming video technology.
The companies already have a relationship, struck in March, that makes their internet technologies compatible. Customers which use Move's technology to stream video online can also use Microsoft's Silverlight to include interactive elements such as branding and navigation in the videos.
In addition to the Microsoft investment, Move also says that it will support Windows Server-based encoding, Microsoft codecs and Silverlight Digital Rights Management.
The investment could help Microsoft better compete online with Adobe's Flash. Silverlight, introduced last year, is Microsoft's response to Flash.