According to Jack Schofield:
Symbian was spun off from Psion as a way of making it independent, and a number of companies own pieces, including Sony Ericsson, Panasonic, Samsung and Siemens. However, Nokia is now offering to buy the 52% of Symbian that it doesn’t already own, for €264 million, and says it will make the system open source.
This is good news because making it open source it will strengthen Symbian’s market share on mobile phones, and also increase the proportion of mobile phones and similar devices running on free software. And remember, free software is freedom software: if means that when you use an electronic device, it’s more likely to do what you want it to do, not what corporations and governments want it to do.