I have personally tested DynamIP with Windows 95, Windows 98 and Windows NT 4.0 (SP4). Most of the stuff (with the exception of the functionality related to the IconTray and RAS dialing) is working fine with Windows NT 3.51 (you must have ServicePack 5 installed, though). However, it's definitely not working with any of the older Windows versions like Windows 3.11, etc...

The memory footprint of DynamIP is relatively large (about 7MB), but usually not more than about 3MB are actually held in RAM (these numbers include code and data). Don't ask me why this thing is so huge as I've tried various things to reduce the memory requirement without much success (a similar app written in Oberon has a footprint of 0.4MB...). The CPU load, however, is minimal.