Unicode input:
  Implementing \U'xxxx' to access Unicode characters directly.

  Making groff 16bit input-clean.

Separating input and output encodings (similar to LaTeX).

Better selection of paper sizes with -Tps.

Make -Tlj4 work with -X.

Guess man5ext and man7ext variables.

Provide man.sun implementing .TX.

Improve GROFF_PRINT macro in aclocal.m4.

Provide a `check' target.

Provide a `bindist' target.

Implement tmac.bib in terms of tmac.s.

Support long options using GNU getopt.

Catch the following error in -me:
.(z
.(l C
.)z

Arrows for next/previous page from R5 xditview.