It's 25 years since a young programmer from Finland called Linus Torvalds proposed a "free" operating system for desktop computers. Linux, as it became known, would go on to power lots of devices we now use, wear, and carry. We look at its legacy and ask Martin Percival of Red Hat whether it will still dominate computing in the future.

Plus, the messaging platform WhatsApp says it will begin showing its users adverts. Is WhatsApp going back on its original ethos, or is it a fair way for its owner Facebook to recoup some of the billions it spent to buy the company?

And we talk to the creators of a phone-based system that traders in Kenya can use to combat corruption when they import goods from neighbouring countries. Presented by Rory Cellan-Jones, with special guest Kate Bevan, and Chris Foxx from the BBC Online tech desk.

(Image: Linux mascot "Tux" penguin in front of a laptop, Credit: Thinkstock).