Geedot aims to be a lightweight, fully (and only) HTML 4.01 and CSS compliant and functional web browser for X. It uses the gdtoolkit widget set which is very fast and lightweight - yet also infinitely and easily expandable.
Postilion is an E-mail client (MUA) for the X-Windows system. It is based upon the TkRat code base, and intends to look and feel like the Mail.app program from NeXT. It supports several languges, and offers a robust feature set.