It's the portable part of this app's title that's important. This publisher doesn't create the Sunbird calendar, he leaves that to Mozilla. All he does is add a launcher to it, allowing you to take your calendar anywhere.
Suffice it to say that Sunbird is a good calendar program that's as easy to use as other Mozilla-developed tools. The distinctive feature of the free Portable Sunbird is the ability to easily take your calendar with you. With a couple of clicks, users can quickly store their calendar on a USB or CD. The process proved to be quick and reliable in our tests, with saved calendar information all present and accounted for when exported from the portable device.
For those without a laptop who travel often, or for anyone who uses multiple computers in a day, this can be a great way to keep on task no matter where you are. If you don't currently have a calendar program, Portable Sunbird offers all the conveniences of Mozilla's Sunbird with the added benefit of easy portability, and it's offered free of charge.