ISilo

iSilo is a document reader available for Palm OS, Pocket PC, Windows Mobile Smartphone, Symbian UIQ, Symbian S60, and Windows CE Handheld PC handhelds, Windows computers as well as Apple iPhone, Android, Windows Phone 7 and HP webOS smartphones. iSilo has direct support for reading these document types: iSilo 4.x, iSilo 3.x, iSilo 2.x, Palm Doc, and plain text files (.txt). However it has largely fallen out of use due to its one-way nature — documents can be converted to iSilo format, but not back out for editing. Other formats, such as epub use open standards, are easily edited or converted, and achieve similar compression rates.

iSilo 4.x: The iSilo 4.x document format builds on the iSilo 3.x document format with extended capabilities supported by and to be supported by iSilo 4.x. Documents in the iSilo 4.x document format can also be opened and read by iSilo 3.x.
iSilo 3.x: The iSilo 3.x document format was designed from the ground up for efficiency with the needs and limitations of handheld devices in mind. Its new architecture provides a flexible and powerful foundation for growth in features and functionality into the foreseeable future.
iSilo 2.x: The iSilo 2.x document format was at the forefront of providing second generation document display for Palm OS handhelds and still does remain a viable platform for doing so.

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