The development of femtosecond (fs) lasers has continued rapidly since the demonstration of fs Ti:Sapphire systems in 1989. Recent research has yielded lasers which offer greatly enhanced performance in all areas. In this document we describe the development of femtosecond lasers with electrical to optical efficiency > 14%, pulse repetition frequencies > 4GHz and compact and stable cavities. We further outline the use of such lasers for the generation of high power visible femtosecond pulses and their application within systems environments for ultrahigh speed data communications, ultrafast optical switching and optical analogue to digital conversion. We also describe progress in the development of femtosecond lasers based on both active and passive semiconductor quantum dot components.