Rated 5 out of 5 stars

It works on Firefox 3.0.11.
If it was not installed, try the next...

1.Extract an install.rdf and a chrome folder from resizeable_textarea-0.1d-fx.xpi.

2.Open install.rdf by the text editor.

3.Change the number of the version in the next part.

exp.
<em:maxVersion>2.0.0.*</em:maxVersion>

<em:maxVersion>3.5</em:maxVersion>

4.ZIP compresses an install.rdf and a chrome folder.

5.Change the name from resizeable_textarea-0.1d-fx.zip to resizeable_textarea-0.1d-fx.xpi.

6.Install it.