The kernel supports 192 threads per appplication by default, but I find it amazing that the OS allows you to easily change its value to a more desirable number. To do the equivalent in Linux you need to edit a header file and then recompile the kernel, while under BeOS its app_server will lock the kernel completely if your application spawns more than 192 threads as there is no way you can change its value. Another cool trick you can do with OS/2 is that you can turn off and on any additional CPUs you may have, on the fly. BeOS users are familiar with this feature (a great way to test applications under non-SMP machines - different number of CPUs can reveal different kind of bugs found in ones source code), but while BeOS goes up to 8 CPUs, OS/2 (reportedly) scales wonderfully on machines up to 64 CPUs.
The Network settings control panel is great. DHCP, web, ftp, telnet servers, BIND, DNS and other exotic networking software, all can be controlled. A small drawback is that each time you do a big change you have to reboot for it to take effect, but other than that OS/2 seems to be an excellent server platform, extremely fast and stable. I will go as far as to say that OS/2 handles networking throughput and server load better than any other single user operating system ever written.
As I mentioned above, you have to reboot for important changes to take place. However, other changes that mostly have to do with WPS itself can be made on the fly. No apply button is required. Any changes you make are applied immediately, they are done in real time.
OS/2 has a good driver base, there is support for USB, PCMCIA, CD-RW, but as far as I can tell there is no support for encrypted DVD playback. Also, because of the fragile installation, you may have to go through with basic installation as in my case with VESA and no audio or USB. After which you'll then do a selective install from within OS/2. In my case, I also had to find in the installation CD and manually install SciTech Display Doctor which gave me accelerated 2D support for my NeoMagic 128XD graphics chipset.
OS/2 comes with full Java 1.1.8 and Java 2 1.3 support although you have to install the latest version of Java manually as above. The system proves very stable and still fast even when running OS/2, DOS, Win 3.1 and Java applications all at the same time.
We have to also mention the Odin project, which is an effort pretty similar to WINE that allows 32-bit Windows applications to run under OS/2. The Odin project is still in beta, but it works for a number of Windows applications. Opera Software found it reliable enough to base their OS/2 version of the Opera browser on Odin. It was done by recompiling their sources to accomodate Odin and OS/2 needs better.
There are several X servers for OS/2 as well, the most well known being HobLink X. There is a pre-registered version of the X Server on the eComStation CDs via a bulk registation to Serenity Systems. It installed just fine, but when I started the X server it stopped loading and said that I had violated the license and that I must call the company in Germany to resolve the issue. So while there is a full port of GIMP, I can't show you any screenshots or talk about its performance, because the X Server did not load. As a sidenote, you can port and run POSIX applications to OS/2 with the use of the EMX POSIX/2 add-on.
OS/2 has support for software and hardware OpenGL and there are 3Dfx drivers available. Speaking of multimedia, there is QuickTime playback support via a third party application, QuickMotion, and also mpeg, avi and DivX support. OS/2 does not have a near-realtime kernel, however its latency is good enough to do some media processing, but in my opinion, not good enough for powerful MIDI processing. I have not seen support for high-end video or sound hardware, or applications for video editing.
OS/2 supports scripting and in fact it's actively used in all aspects of the OS. The language used is REXX and it's powerful enough to deal with installation issues, component registrations for apps, networking related matters and more.
One of my disappointments in the OS default setup is the FAT32 driver. While there is a FAT32 driver written by a third party included on the third CD, you have to install it manually. And the installation is not what I would call an easy task for Joe User, you have to mess with the drivers, the config.sys, the .ini files, and you have to mess (again) with LVM. Trying to install the FAT32 driver really reminded me of the DOS and Windows 3.1 days. While the OS/2 kernel is excellent, the way the system handles setup is in many ways are similar to the pre-Windows 95 era. Many settings files and command line work mostly done under a DOS or OS/2 terminal.