Software
The Hiptop operating system, referred to as DangerOS, is largely based on Java. For Hiptop development, Danger has its own proprietary APIs, which are a subset of J2SE with their own extensions. Danger introduced support for Java ME, the Java language optimized for mobile devices, to its OS with the release of OS 2.3.
Each Sidekick had an IM client (with AIM, Yahoo Messenger, and MSN Messenger); an Email client with an included T-Mail account; a pre-installed game (Rockets and Rocks or Bob's Journey); an organizer with planner, a calendar, and calculator; a SMS and phone app; a Download Catalog (also called Download Fun Catalog); and a Communities app, which was where social networks were accessed.
A cloud service backed up all personal data like settings, planer, notes, calendar, fotos and all contacts. It was accessible and also editable on a web interface. A factory reseted or new device was able to restore all personal data by signing in with username and password.
To aid third-party software design, Danger has released a comprehensive software development kit (SDK) that contains a Hiptop simulator, development installation utilities, and Danger API information. The SDK is available without charge from Danger's development website.
There is no way to add applications to a standard Hiptop software on the device without the use of the Download Catalog. This is ostensibly done to ensure only tested and compatible software is capable of being installed on a production device.
Application developers can bypass this functionality by using the included programs in the Danger Hiptop SDK to install user-written applications to the Hiptop device directly. To do this, you must apply for a special software key known as a Danger Developer Key. The Danger Development Key is a special security certificate that is provided by Danger that enables the device to be used as a Development Device. This will allow the installation of user-written applications to the device, but will void any software warranty provided by Danger and/or your wireless carrier. Any applicable hardware warranties should still apply.
While DangerOS uses .jar files for applications, they are uploaded to the device in special files called "bundles". Bundle files have the extension '.bndl'. Each bundle file is linked to a specific operating system version and build number. For example, a bundle file for v3.4/155053 (T-Mobile Sidekick 3) would be denied installation on a v3.3/149695 device (T-Mobile Sidekick iD). Installation of bundles require a developer key to be installed on your device if you are using a Production OS. Internal OS builds do not require developer keys.
The Sidekick LX 2009 model runs DangerOS 5.0, which is reported to be based on NetBSD.
Read more about this topic: Danger Hiptop