Newplex is the name of a new CAD font from Dave Edwards Consulting. The font is designed for technical documentation and CAD users.
It features advanced readability, oft-requested special characters, and international characters. It's available in SHX and Truetype formats. You can view a sample of it here.
SHX is the font format read by AutoCAD and some other CAD packages; TrueType is the Microsoft font format that AutoCAD and all other Windows (and under certain conditions, Linux) software displays. (It's not common knowledge, but AutoCAD sill can work with PostScript fonts: you need to run them through AutoCAD's Compile command to convert them to SHX format.)