uMatrix - Point and click matrix to filter net requests according to source, destination and type

uMatrix is a browser extension which let you whitelist or blacklist requests originating from within a web page according to their type and/or destination as per domain name. Much effort has been spent on creating highly efficient filtering engines: HTTPSB filtering engine can hold tens of thousands more filtering rules in memory while having a significantly smaller memory and CPU footprint than other comparable popular blockers.