From what I've found out I can conclude that Scriptish injects scripts differently than Greasemonkey. The code that injects Linterna Mágica in the scope of the page is based on a method [1] explained in the Greasemonkey wiki. The method works on the assumption that the userscript's code is executed inside a function and at run-time this function's body can be used to access the entire userscript. This is achieved by converting the caller function (the one that runs the userscript) to string - .caller.toString();. Scriptish breaks here and complains that the caller object is non-existent.

The work-around is to wrap the userscript inside an anonymous self invoking function - (function() { ... })();. This way the injection code works.

A working code is available in r271. The svn trunk build at the website is now at that revision, but mirrors update at 24 hours, so until then use the direct link. So far the code seems working, but just in case I'm leaving it in testing phase. Please report any new issues with that revision. The Scriptish version tested was 0.1.7 on Abrowser 11.0.

[1] http://wiki.greasespot.net/Content_Scope_Runner

So, it depends on the Scriptish team to make it work with Linterna Magica, is that it?

Linterna Magica used to work fine with Scriptish and Abrowser or Firefox beta in Trisquel 5.

Now, Linterna Magica works fine with Greasemonkey and Firefox beta (12) with gecko-mediaplayer as a plugin on Debian wheezy (testing).