Easytask multitasking kernel - Multitasking kernel, and RS232 serial driver. Easily programming real-time applications for PC or embedded technology. Borland C++, Watcom C++, and Pascal. - http://www.oritech.com/easytask/
OptiVec - Comprehensive libraries for vector, matrix, and complex math functions. Hand optimized routines written in Assembler for speed and accuracy. - http://www.optivec.com/
CMATH - Assembler written complex number math library (single, double and extended precisions), intended as a high-quality replacement for the available C++ complex class libraries, and as an add on for Pascal or Delphi. - http://www.optivec.com/cmfuncs/
Irie Tools - Irie Pascal for DOS is a Pascal compiler and interpreter. Both the compiler and interpreter are command-line based. - http://www.irietools.com/iriepascal/