Sorry, they are Plugins as listed under 'Tools' 'Plug-ins'.
Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 (.NET CLR 3.5.30729)
Here's the Add-ons:-
Adblock Plus 1.1.3
AVG Safe Search 9.0.0.812
British English Dictionary 1.19
Crawler Toolbar 1.3 (disabled)
Dictionary.com Toolbar 3.5.0.145
Flash Video Resources Downloader 1.0.3
Forecastfox 0.9.10.2
Java Console 6.0.15 disabled
Java Console 6.0.16 disabled
Java Console 6.0.17 disabled
Java Console 6.0.18
Freegle Member Plugin 3.0.112
M/S .NET Framework Assistant 0.0.0