The main purpose of the pdfTeX project is to create and maintain an extension of TeX that can produce PDF directly from TeX source files and improve/enhance the result of TEX typesetting with the help of PDF. When PDF output is not selected, pdfTEX produces normal DVI output, otherwise it generates PDF output that looks identical to the DVI output.
An important aspect of this project is to investigate alternative justification algorithms (e. g. a font expansion algorithm akin to the hz micro--typography algorithm by Prof. Hermann Zapf), optionally making use of Multiple Master fonts.
pdfTEX is based on the original TeX sources and Web2c, and has been successfully compiled on Unix, Win32 and MSDOS systems.
These details are provided for information only. No information here is legal advice and should not be used as such.