I want to know what all helping tools that are available for writing XUL documents which are used by Firefox Add-on developers these days.
Two methods:
Method 1: Live Editor: ted.mielczarek.org/code/mozilla/xuledit/xuledit.xul need to use white list addon before can use the site though: addons.mozilla.org/en-US/firefox/addon/remote-xul-manager
Method 2: Restarltess addon dev and installing with something quick like GitHubExtensionInstaller with Pull Request 10 where save does not need to be made for testing: https://github.com/diegocr/GitHubExtIns/pull/10 You can then edit the XUL file, and without comitting, click install, and it will pop open your xul file right there (the bootstrap.js tells the xul file to popup). For example was was done on this repo: https://github.com/Noitidart/l10n/tree/bugzilla_id%3D1121322 This is the method I prefer because all dependencies, chrome.maniest etc are in play.