The zTXT compression is done using zLib, a Free compression library released under the zLib License. This results in much smaller files than with the PalmDoc method. For example, the Project Gutenberg e-text of "The Merry Adventures of Robin Hood" is approximately 600K in size. Compressed as a zTXT, it is only 261K in size, while with PalmDoc it is about 330K. Since the Palm Pilots do not have very much memory, this is a big savings.

"Weasel Reader":

• Reads documents in zTXT and PalmDoc formats
• Uses zLib for compression (ala gzip and pkzip)
• Decompresses the text as you read
• Hi-res available on devices which support it
• Uses an age-based cache to keep the most relevant data in memory
• Remembers where you stop reading
• Full bookmark support. Add/Remove/etc.
• Jump around to arbitrary places in the text
• Number of allowable documents is limited only by memory
• You can select the text you're reading to copy it into other apps
• Export text to the Memo Pad
• Beam Weasel or books to other Palms or to a PC
• Full annotation support with references to where the annotation occurs (zTXT only)
• Search capability
• Smooth autoscroll or screen wrap-around autoscroll options
• Disable the onscreen controls and read full-screen
• Invert the screen
• Rotate the screen by +90 or -90 degrees
• Per-document preferences (optional)
• Multiple language hyphenation support
• Supports read-only documents in ROM/Flash/etc.
• Supports Palm OS VFS for reading from expansion memory cards/sticks
• Supports jog dial on Sony PDAs
• Absolutely 100% Free Software (licensed under the GPL 2.0)

• Major new features include fixed support for the Palm 5-way navigator (i.e. d-pad buttons) plus the ability to remap keys to perform user specified actions while reading.
• There is also a new "Most Recently Read" list maintained by Weasel Reader to help frequent users keep tabs on what they are currently reading.