Hi zerker, Warp 3 is fine for most applications. 😎 Warp 4 is more user friendly, though, because more things do work "out-of-box".
It also supports more modern things, like ATAPI CD-ROM drives, the GRADD display drivers and DIVE API (comparable to DirectDraw in the Windows world).
Warp 4 is also more compatible with Windows programs, since it always ships with a special version of Windows 3.x (WIN-OS/2) and
also can run ODIN (a bit like WINE on Linux; early versions of it can also run on Warp3 with a little bit of DLL copying).

Plus, it comes with complete package of networking software (with parts borrowed from OS/2 Warp Connect).
It also got one important fix - the Synchronous input queue (SIQ) issue was resolved.

Some time ago we dicussed Warp4 in Vogons' thread the Ultimate OS/2 Warp 4 machine.

Once you've applied the latest Warp 3 fixpack, the kernel is at Warp 4 level, so GRADD should Just Work, same with storage drivers, etc. The interface has improvements in 4.

However, the networking will be at a lesser level than in Warp 4, and there's a few components Warp 4 was bundled with that aren't in Warp 3 Connect (of course, there are also networking less versions of Warp 3, which isn't the case with 4..). In practice this will make little difference.

The SIQ issue was first fixed in Warp 3, I think around Fixpack 17 or so (the first Fixpack the fix began being included was FP12, an internal/developer only fixpack).

Thanks for the replies guys. I'm still flip-flopping on whether I want to get OS/2 at all. I suspect I'd probably use it for a couple days then move on. For now, I'm going to concentrate on my other projects.

At the time I loved OS/2, but it's no longer 1996, or even 1999 when I finally moved to NT 4. It's fun to play Galactic Civilisations 2, but there's not a lot else that isn't better run elsewhere. If you do run it, I would recommend doing it in a VM.

Warp 4's biggest improvement was networking and hardware support, and you lose out on nothing by not going for Warp 3 so go for that, even though Warp 3 is especially nostalgic to me..

OS/2 Warp 3/4 were my life between 94-98, I will always remember the wonder of installing Warp 3 for the first time in 94 from something like 50 floppies onto a DX4-100 because the Student Edition didn't come on a CD-ROM, connecting to IBM.net and seeing the WWW for the first time. Access was 20 hours per month (crazy righr?) but it blew my teenage mind. However, after completely skipping on Windows 95 and pretending OS/2 was not going anywhere, even I had to move on by 98.

I actually want to install Warp 4 as a novelty on my current go-to Retro PC (P166MMX) at some point, but I'll have to look into triplebooting it alongside Win98SE and Linux/FreeBSD. The problem is that there is really not much left to do with Warp 4 anymore; it was a great system to get connected with in 95, dial-up and tcp/ip support out of the box and I could run my BBS on it while even doing MSDOS gaming on it. These days, it's like setting up an MS-DOS PC, except there is no software to be nostalgic about. I love Warp. I always will. I just don't want to install it and be disillusioned I guess..

Triple booting is easy, quad booting (BSD) may be tricky. Install Boot Manager first and use OS/2's partitioning tools to make all the partitions and determine if all the boot partitions are within the required cylinder limit. Primary partition for 98, logical for OS/2, Linux, and FreeBSD.

Linux boot partitions are easy, as / (well, /boot) does not have to be large. BSDs on x86 are more of an issue, because if MBR partitioning is used it's one large MBR partition subdivided by disklabel which may go beyond the cylinder booting limit. Create two partitions which will be allocated for BSD (boot, below the cylinder limit of Boot Manager), and another partition immediately after it that will contain all the other data. Then override the parameters in BSD install for the area used by BSD, ensuring that the disklabel for / starts at, and is entirely within, the boundaries for the first BSD partition created.

There's not a lot to do in OS/2 though, I've a fair bit of software from the time, but the Internet is unusable for browsing unless the system is fast, running the very latest kernel, and up to date libraries. Seeing as it never had 3D acceleration, that's why I recommend using a VM these days.

Patching the install CD with UPDCD is a bit of a faff but definitely worth it. However, it needs an existing OS/2 system (or at least a recovery one) to work.