Be careful with old versions!
These versions are displayed for reference and testing purposes. You should always use the latest version of an add-on.
I write user data (contents.xml) to "ProfD"/MyContetns/ or to "Home"/.mycontents/ if the former doesn't exits.
'Tools menu item": I've set accesskey 'C' and key 'Ctrl + Alt + M'.
I've replaced 'parseFromStream' with 'parseFromString.
I've fixed some errors: frequency count using D&D, properties.
By pressing Ctrl key while clicking on a link, the referred page can be opened inside the application. This is especially useful on the first page (Google) when you add a new page to your contents.
By clicking on a link in the content, a new page is opened in a new tab in FF, instead of a new window. I hope you like it, it needs less memory.