All of these are in the public domain:

p4

pascal compiler - niklaus wirth, et al ( 1976 )

web

literate programming - donald knuth ( 1981 )

super

super pascal ( parallel programming ) - per brinch hansen ( 1993 )

p5

ISO 7185 compliant extensions to p4 - scott moore ( 2009 )

xdp

TP 3.0-style pascal compiler - vasiliy tereshkov ( 2010 )