
It uses the Series 60 2nd Edition, Feature Pack 3 user interface and the Symbian OS 8.1a operating system. Recent revisions also ship with Version 2 of the Nokia Lifeblog software.
The N90 does not have a built-in hard disk drive like the Nokia N91 but it features 31 MB flash memory and is usually packaged with a 64 MB or 128 MB in-box DV-RS-MMC memory card. Nokia continues its recent tradition of bundling a USB data cable with the phone, previously an aftermarket item priced close to US$40. A 1 GB memory card allows storage of four hours of video on the handset.
More information at Wikipedia..