The Microsoft OS/2 SDK includes pre-release builds of OS/2, beta development tools, sample code, and loads of documentation. These were released prior to the OS/2 1.0 and 1.1 releases. Microsoft charged $3,000 in 1987 for the SDK. It was criticized as overpriced, buggy, and slow.
These were superseded by the smaller and less expensive Microsoft OS/2 Programmer's Toolkit
Much more information can be found here: OS/2 Museum, OS/2 Beginnings
The Microsoft OS/2 2.0 pre-release SDK contains many features that differed from IBM's OS/2.
The same desktop GUI as OS/2 1.x, a flat 32-bit application environment, unlike OS/2 1.x, the ability to use 16-bit drivers, DOS compatibility implemented using a protected mode 386 virtual DOS machine, and Microsoft LanManager networking.
Several resources with more information:
An actual look at Microsoft OS/2 2.0 https://virtuallyfun.com/2024/02/26/an-actual-look-at-microsoft-os-2-2-0/
The Future That Never Was http://www.os2museum.com/wp/the-future-that-never-was/
Download name | Version | Language | Architecture | File size | Downloads |
---|---|---|---|---|---|
Microsoft OS2 SDK 2.0 Pre-Release 2 (June 1990) (5.25-1.2mb) | Pre-Release 2 (June 1990) | English | 21.11MB | 1 |