Nokia has made a major update to the Linux PDA it doesn't want you to think is a Linux PDA, the 770.

Available for free download, OS 2006 edition introduces version 2.0 of Nokia's Linux platform, Maemo. Included are system level performance improvements, support for VoIP clients, and Google Talk. There's a full feature list here.

However, according to Nokia, the update breaks backward compatibility.

"Installed applications designed for OS 2005 will not be compatible with OS 2006 edition and will not be restored even from backup," warns the company.

So, er ... look out.

OS 2006 can be downloaded from here [Nokia USA] or here [Nokia's Maemo site], and requires a Windows PC with Net 2.0 framework installed.

User reports are as ever welcome.®