Which browser ids are compatible with CACHEbox?
select t1.id from web_client_accelerator as t1 join accelerator_compatible_browser as t2 on t2.accelerator_id = t1.id where t1.name = 'CACHEbox'
Name those browsers.
select t3.name from web_client_accelerator as t1 join accelerator_compatible_browser as t2 on t2.accelerator_id = t1.id join browser as t3 on t2.browser_id = t3.id where t1.name = 'CACHEbox'
Intersect that with those compatible with Fasterfox.
select t3.name from web_client_accelerator as t1 join accelerator_compatible_browser as t2 on t2.accelerator_id = t1.id join browser as t3 on t2.browser_id = t3.id where t1.name = 'CACHEbox' intersect select t3.name from web_client_accelerator as t1 join accelerator_compatible_browser as t2 on t2.accelerator_id = t1.id join browser as t3 on t2.browser_id = t3.id where t1.name = 'Fasterfox'