While sifting through a large number of trees I came across some 'must-have' features I could not find in any of the available tree viewers (or at least those I could install due to dependency problems). After cannibalizing a few older programs of mine I finally came up with a bare bones tree viewer for Newick format trees. The must-have features included editing of names for the nodes in the tree, being able to highlight leaf nodes by regular expression searches (useful if looking for sequence 'X' in a tree with 500 sequences) and the ability to compare the tree with the corresponding alignment. Since then the tree viewer has been extended to include viewing of subtrees, collapsing nodes with bootstrap support below 'x', abstract representation of whole branches of the tree and other features.
NOTE: Still under development. Bug-reports, must-have and nice-to-have features are appreciated.