A decent LaTeX2e installation (e.g. teTeX for unix) not older
than 1995/12/01.
Python 2.3 or later to convert old LyX files and for helper scripts
+ (note that you need at least Python 2.3.4 for exporting LyX files
+ to a pre-unicode format, as previous versions are affected by a bug
+ about the normalization of unicode strings)
How does the LyX version scheme work?