I use and endorse the following support software for editing Wikipedia:
- Zotero, to collect and organize references; makes it easy to add properly formated references to Wikipedia articles.
- Navigation popups, shows the first paragraph of an article if you hover over a link, gives easy access to editing functions, article history and diffs.
- WikEd, nice and quick search-and-replace feature for the editing text box, plus syntax highlighting and quick preview.