Hello,
It would be nice if:
1. Maximum length of group's name (that displayed in groups panel) match the current width of groups panel as is done in Citavi, Zotero, Mendeley, etc.
2. Part of group's name that does not fit into the width of groups panel wraps to the next line(s) as is done in Biblioscape and Cherrytree.
P.S. Willing to pay for implementation of this features, if it is within my financial capabilities. I would like to know about the cost.
This should be implemented in the latest development version (http://builds.jabref.org/master/). Thanks for the suggestion!