To address antitrust concerns in Europe, Microsoft says that it will open up certain technologies, making it easier for partners' and competitors' products to interoperate with Windows. Microsoft's concessions directly address the two chief concerns in the European Union (EU) antitrust case against the company. The EU antitrust case somewhat mirrors Microsoft's legal problems in the United States, but the European case focuses on Microsoft's server technology as well as its desktop technology, which was the target of the US case. The company had previously agreed to open up other technologies as a result of the European investigation; today's concessions are the second set of concessions Microsoft has made to the EU. "We're working to find more ways to share information that we think is helpful to the industry," said John Frank, a senior corporate attorney for Microsoft Europe.

In August, the EU served Microsoft with a legal complaint, claiming that the company failed to share Windows-compatibility information with competitors in a bid to extend its desktop monopoly to servers. The EU also says that Microsoft bundled its media player in Windows solely to shut out competition, a complaint Microsoft hasn't yet addressed.

Microsoft's latest concessions regard its Common Internet File System (CIFS) and Server Message Block (SMB) protocol technologies, which Windows servers and desktop machines use to communicate over networks such as the Internet. Microsoft says that it won't assert its intellectual property rights over CIFS and will instead offer it openly as an Internet standard. In August, Microsoft will also begin licensing its proprietary enhancements to SMB, giving third parties the information they need to write compatible products. Some SMB-compatible products already exist, such as Samba, an SMB add-on for UNIX and UNIX-like OSs such as Linux. But because the SMB format was proprietary, Samba's developers had to reverse-engineer SMB, which changes somewhat with each Windows version. Microsoft's opening up of SMB is a big win for UNIX/Linux/Windows interoperability.

Late last year, Microsoft had pledged to open up the proprietary extensions the company made to Kerberos, a network security protocol, though that hasn't yet happened. This action will make Microsoft's server security technology available as a standard that other interoperable products can use.