overview of everything currently installed on the system. Data can be synchronized with a PC via a USB connection, and the user's files can be accessed using the standard Removable Storage Device protocol. A new update (Version 21.2011.38-1.002) was released onto the Nokia N900 on 2 November 2011 as an OTA update. The new version mostly consists of security updates. This is considered to be the final official update to Maemo 5/Fremantle shipped by Nokia. Further development of Maemo 5 happens as a community effort in Maemo-CSSU. Features Updating Maemo devices can be updated using a simple flashing method with a computer over USB. Since Diablo (Maemo 4.1), Maemo supports "Seamless Software Update" (SSU), which allows incremental operating system upgrades "over the air" using the Advanced Packaging Tool, without the need for a full flash with every update. Flashing remains available as a way to start over from scratch with a clean installation (much like formatting a hard drive and reinstalling an operating system on a PC). Security The quick start guide for developers warns that Maemo security concentrates on preventing remote attacks (e.g. by wireless networking and Bluetooth). It also warns that Maemo's root account has a trivial default password (user: gainroot, password: rootme) which needs to be changed before enabling remote access. Maemo employs a numeric security code as a way to lock the device's controls and display independently of the root password, to help prevent unauthorised access. Software architecture Maemo is a modified version of the Debian Linux distribution, slimmed down for mobile devices. It uses an X Window System-based graphical user interface using Xomap and the Matchbox window manager. The GUI uses the GTK+ toolkit and Hildon user interface widgets and API. BusyBox, a software package for embedded and mobile devices, replaces the GNU Core Utilities used in Debian-proper to reduce memory usage and storage requirements (at the expense of some functionality). ESD is used as the primary sound server, and GStreamer is used by the shipped media player to play back sounds and movies. The formats supported by GStreamer can be extended by compiling GStreamer plugins in scratchbox (Maemo SDK), which was done, for example, to bring Ogg support to the platform, as well as experimental features such as WebM and VP8 after they were announced by Google. Third-party media players can access GStreamer directly or via "osso-media-server". Window management is handled by the Matchbox