Moreover, Windows XP Professional x64 Edition also supports NX-bit to the full extent. Just like in Windows XP Professional SP2, NX-bit check can be disabled for individual applications.
The situation with available applications is a little bit more curious. As for the native 64-bit programs developed specifically for Windows XP Professional x64 Edition, they are still not that numerous. Besides those few 64-bit applications included into the package, such as 64-bit version of the Internet Explorer, there are really few other programs you can now get for your Windows XP Professional x64 Edition. Among the Windows software developed by other companies, which has already been ported for the x86-64 architecture, I would like to point out Mozilla Firefox, Avast Antivirus 4.5 and McAfee Enterprise 8.0i antivirus software, and a number of small utilities for system and hardware configuring. Moreover, it is great that they also have 64-bit beta version of Microsoft .Net Framework.
Now I would like to say a few words about the work of 64-bit browser versions. The thing is that Internet surfing with the 64-bit browsers appears somewhat complicated because there are no 64-bit versions for many popular plug-ins. Today we don’t know anything about the new 64-bit plug-ins other than Macromedia Flash, Shockwave and Java VM. As a result, you will have to surf around many web-sites using ActiveX components with the 32-bit browser versions only. For this particular purpose they also include a 32-bit Internet Explorer version into the OS package as well. The funny observation of ours: among the sites, which do not work with 64-bit browsers we also discovered Windows Update site :)
However, do not be too frustrated about the absence of native 64-bit applications for Windows XP Professional x64 Edition. The big advantage of this OS is the availability of a special x86 Windows on Windows 64 (WOW64) emulator, which allows using the regular 32-bit software. Almost all 32-bit applications will work in Windows XP Professional x64 Edition without any problems. Although there are a few exceptions here. For instance, Windows XP Professional x64 Edition will not support some 32-bit versions of antivirus software and Starforce copy protection system, which will prevent you from running some games in the new OS too. This is also true for the old 16-bit programs from the times of good old Windows 3.XX: these applications will not work in Windows XP Professional x64 Edition at all.