For far longer than any of its developers would care to recall, Wine, the best program to use in Linux to run Windows applications, has been in development. Now, at long last, Wine 1.0 is scheduled to be released. To be exact, Wine (Wine is not an emulator) 1.0 should appear June 6, on the project's 15th birthday. While at this point there are 1,229 Windows applications that install and run out of the box, only four Microsoft applications (Photoshop CS2, PowerPoint Viewer 97 and 2003, and Word Viewer 97 and 2003, and Excel Viewer 97 and 2003) are being considered as critical for the 1.0 release. The reason for this, the Wine developers explain in the Wine 1.0 release plan, is that "expanding that list is that each new app adds a huge amount of testing to each release."
Note: This has been a great addition that has allowed me to continue to use my Windows programs that I liked.