-- Database schema
| Web_client_accelerator : id [ INT ] primary_key , name [ TEXT ] , Operating_system [ TEXT ] , Client [ TEXT ] , Connection [ TEXT ] | browser : id [ INT ] primary_key , name [ TEXT ] , market_share [ INT ] | accelerator_compatible_browser : accelerator_id [ INT ] primary_key accelerator_compatible_browser.accelerator_id = Web_client_accelerator.id , browser_id [ INT ] accelerator_compatible_browser.browser_id = browser.id , compatible_since_year [ INT ] |
-- -- Show the accelerator names and supporting operating systems that are not compatible with the browser named 'Opera'.

SELECT name ,  operating_system FROM web_client_accelerator EXCEPT SELECT T1.name ,  T1.operating_system 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 T3.name  =  'Opera';