US aid worker Peter Kassig's parents said they were "heartbroken" by the death of their son, after his beheading by Islamic State militants was shown in a video.
Hungary's Prime Minister Viktor Orban dismissed corruption claims cited by Washington as the reason for US entry bans on six senior Hungarian officials.
President Barack Obama said the United States cannot "carry the world economy on our back" and urged G20 leaders to work harder to create jobs by revving up growth.
Microsoft released a test version of Skype that lets people make Internet calls from web browsers, eliminating the need to install special applications.
Facebook said it is making moves to reduce the number of promotional posts that pop up in timelines, in response to users' demands for fewer advertisements.
Hollywood's A-listers gathered in Los Angeles for a film festival that may not be well known but nonetheless shines an early spotlight on awards season.
The history of rock 'n' roll has been attempted in exhaustive compilations and encyclopedic guides. The Foo Fighters are trying the feat in a 42-minute album.