From Just Solve the File Format Problem
NeoDraw is a vector graphics editor for Windows 3.x, developed by NeoSoft. It has a native .teo graphics format.
Not to be confused with:
- NeoOffice Draw - a component of NeoOffice
- NeoPaint - a better-known NeoSoft product 
TEO files are observed to start with bytes
'T' 'e' 'o' 0x1a.