Microsoft offers two kernel-mode debuggers, WinDbg and KD, for no charge. However, the full capabilities of WinDbg and KD are available only when two interlinked computers are used. SoftICE therefore is an exceptionally useful tool for difficult driver related development and continues to function well even with Microsoft's latest operating system versions.
SoftICE is also popular as a software cracking tool.
SoftICE/W (for Windows) was developed in the 1990 time frame, and was instrumental in the Writing of "Undocumented Windows", by Andrew Schulman, David Maxey, and Matt Pietrek. SoftIce/W was derived from an earlier, lesser known product, SoftICE for Netware (32-bit protected mode). One of the key advantages it had over Microsoft's debuggers is that it enabled single machine debugging, rather than requiring a second machine to be connected over a serial port.
The principal developers of SoftICE were Dom Basile ('Mr. SoftICE'), Tom Guinther (Kitchen Sink, Symbol Engine), Gerald Ryckman (Video Drivers and Kitchen Sink), Ray Hsu (Video Drivers W95), and Dan Babcock (SoftICE/NT 3.1/3.5: Universal Video Driver, Symbol Engine), with contributions by a variety of NuMega developers including Frank Grossman, Jim Moskun, and Matt Pietrek.
In 1995 the codebase for SoftICE/95 was ported to run on the Windows NT platform.
Newer versions of SoftICE patch deep into Microsoft Windows. As such, old versions of SoftICE are rarely compatible with new versions of Windows. Compuware therefore offers SoftICE as a subscription so that it can be kept up to date and in sync with the latest Microsoft Windows version.
An open source kernel debugger similar to SoftICE named Rasta Ring 0 Debugger is available on the project page It provides low level debugging for Microsoft Windows, Linux, OpenBSD, NetBSD, and FreeBSD. As of the time of this writing a Mac OS X version is in the works.