IBM UK has agreed a joint marketing agreement with Alsys Ltd, the Henley-on-Thames based Ada language specialist: under the agreement IBM is to offer Alsys Ada compilers and tools on a range of computer systems from PS/2 micros to the 370 range of mainframe systems; the compilers provide a common user environment allowing the software engineer develop applications identically on a PS/2 under PC-DOS or a 9370 under VM/CMS; Alsys has also announced an Ada compiler for Compaq computers running OS/2 and the new product incorporates a complete multi-library system and supports a range of programming tools; the compiler runs on both 80286 and 80386 Compaq computers and Alsys claims the advantage of OS/2 over PC-DOS is that it can handle simultaneous operations such as editing code while compiling in background.