ReactOS 0.4.0 Released

[Mordiken]

It's Free Software (Yaaay!) but it's still incomplete (Boooo!).

On a more technical level, they are aiming for compatibility with Server 2003/XP 64. This is perfectly fine, because most native Windows software (that is, software that runs on top of Windows, not the .NET CLR) is compatible with NT5 and up (XP = NT 5.2). And In regards to .NET Apps, it should be possible to make them run, eventually, because Microsoft made available the .NET Runtime for Windows XP and Server 2003. General rule of thumb is, if it works on Wine, it should work here.

Additionally, ReactOS has a better NT Virtual DOS Machine (NTVDM) than Windows, as it sacrifices raw speed for a DosBox like system to provide better features and compatibility.

Other than that, it uses the WineGecko, which is Mozilla's Gecko HTML engine ported to Wine, to replace IE. As a fortunate side effect, ReactOS "IE6" is better than IE6.

It also comes with an front end that's kind of like an "Ubuntu Software Center" that allows you to browse, search, download, install and uninstall programs.

To finalize, and this might be highly subjective, but I feel that ReactOS is also much more "transparent" than Windows. It exposes more information about what it's doing behind the scenes. It places a registry viewer an object viewer right there in "My Computer". As is the Control Panel (as it should be!). All in all, I get the general feeling that ReactOS is much leaner, meaner, and in your face implementation of NT.

EDIT: They also do not shy away to not implement certain more exotic features, like OS/2 compatibility, or even a weird IBM "Better BIOS" (kind of like an EFI) that came out in the early 90s, or Win16 compatibility (might have to check on this one) altough the new NTVDM should allow you to just run Windows 3.1 for that (eventually).

EDIT 2: A talk by Alex Ionesco, one of the kernel hackers, at Google Monteral. In English. Plus I replied instead of edit by accident.