Thanks for the previous advice given on this question but still need
further clarrification of a definate yes/no answer before risking my
firefox profile.
Question:
If i am searching for firefox extentions and see and extention listed
as: compatible with "whatever up to V.1.0"
1) Each extension comes with a <em:minVersion> and <em:maxVersion> which
is set by the author. It represents his best guess about which versions
of firefox his extension can work with.
2) You can over-ride these by either doing a system wide change to the
browser (change app.extensions.version) so it appears to be a
earlier/later version in terms of installing extension or change the
extension (simple text edit) so it accepts installation on older/newer
browsers.
3) Some extension writers set their extensions to allow installations on
up to 2.0 or even 5.0! but this is risky, since they cannot predict how
the extension system will change. Firefox will allow the installation but
might break.
Does this mean that if i have version 1.0.2 this extention is not
suitable or does "1.0" include any numbers following 1.0 upto any
future 2.0 release????
Technical details can be found here
"How Firefox Determines Compatibility
Firefox uses the pref app.extensions.version to determine Extension
compatibility for this release. When an Extension is installed, Firefox
makes sure that app.extensions.version lies within the range set up by
the Extension's install.rdf file using minVersion and maxVersion. If
app.extensions.version is less than minVersion, a newer version of
Firefox is required to install the Extension, if it is greater than
maxVersion, Firefox is too new to install the extension.
The app.extensions.version pref will be incremented every time there are
changes that might break extension authors, or every minor release, i.e.
0.9, 1.0, 1.1, etc. If a point release contains changes (heaven forbid)
that might break extensions, we'll rev it then too. Every time we rev
this pref, we will publically announce our intent to do so.
In most cases, this pref will stay the same between minor versions. For
example, Firefox 1.1 ships, with app.extensions.version set to "1.1".
Hypothetical security firedrills cause 1.1.1 and 1.1.2 releases, but both
of these follow-ons still have app.extensions.version set to "1.1" -
since there are no changes in the subminor releases that cause extension
incompatibility, we don't want to break Extensions compatible with 1.1. "
http://www.mozilla.org/projects/firefox/extensions/update.html