Sorry folks, but it DOES work with FF5. I'll repeat: this wonderful add-on DOES work with FF5. With very little research (ie went to support page-duh) and found a simple solution.

https://addons.mozilla.org/en-US/firefox/addon/add-on-compatibility-reporter/?src=api

* You should have the add-on-compatibility "add-on" installed anyway. I think an apology is due the TinEye guys. Lets be fair.

It's the best firefox plugin to avoid duplicate content and copyrights issues. With it, it's really simple to find the original image and author.

it messed up my computer it has a virus

This addon supports FF5, You just have to edit install.rdf file inside (you can open xpi with winrar) to this:
1.5
5.0.*
Please fix this issue.

Thanks very good

Excellent add-on. Please update for FF5.

FF5 support please!!

Now that search by image from Google is out I think I will remove this now. It was certainly good while it lasted.

Been using this for a while now, would love to see an update for the 5 beta.

You know, it's cool. It works.
Tineye's database isn't perfect but it'd be hard to have everything.... It's the best reverse image search on the net and this add-on is convenient.

Fantastic, and I'm suprised how fast it is!

"Not compatible with Firefox 3.6.16"
I cant use this addon until you update it for the latest version of firefox!

Good and getting better.

Indispensable for Forensics Work, such as debunking Social Network 'IdentityPhotos'. ~Hawk~

Awesome.

This add-on is an example of those things that once they appear, they become indispensable.

Very useful !

Very useful ! I use it every day to find things ! Like larger or better version of an image seen on the internets.

Simple, useful, and do just what is it for :)

Would be nice if people could contribute some way other than PayPal. Stopped using them a very long time ago after their new `rules`screwed up my account.

Excellent - does as it says on the packet and only gets better with time

+5 for the porn tag

Amazing, does exactly what I want and I have never encountered any problems! 5/5, definitely!

Please add TinEye to context menu on Windows.

I do like it and find it very important in knowing if an image is real or just faked like in those fake news sites advertising fake jobs. If the same picture of a work at home mom is used under many different names then I know not to trust it! TinEye helps me with this! Thanks TinEye!

I love this service and the plugin.
It would be nice if the plugin could also automatically recognize and submit local files when viewed in the browser (e.g. file:///E:/pictures/Park.jpg).
Notice those similar plugins for other sites:

GazoPa Similar Image Search
https://addons.mozilla.org/en-US/firefox/addon/14423/

Cydral Image Search Engine
https://addons.mozilla.org/en-US/firefox/addon/244885/

Who stole my pictures?
(for the Russian Yandex. It also adds TinEye search but without the advance options, so you better hide this using Menu Editor - https://addons.mozilla.org/en-US/firefox/addon/710/)?
https://addons.mozilla.org/en-US/firefox/addon/266838/

Japanese one without name:
https://addons.mozilla.org/en-US/firefox/addon/264495/

Image Search Options
(adds search in several useless Manga databases, but it also includes TinEye and GazoPa and option to put all in a submenu, so it might be all-in-one plugin when further developed):
https://addons.mozilla.org/en-US/firefox/addon/93451/