The folks at Gallery, an online photo album organizer, are working hard developing the newest version of Gallery in the 1.x line...Gallery 1.6. Gallery 1.6 is currently at Alpha 2 which means that the software is intended for testing purposes and not for use on production servers. If your confused with what I just said then I recommend you wait installing Gallery 1.6 until it has been fully released.
The two primary goals for this new version of Gallery were HTML 4.01 compliance and easier visual customization. Because so many of the code changes were centered around the visualization, it is unlikely that your previous 1.x themes and styles for Gallery are fully compatible with Gallery 1.6. For a highlight of changes and new features as well as download links in Gallery, check out the official announcement located on the application's home site.
The current development schedule calls for Gallery 1.6 to be released at the end of November, 2006. In in the Spring of 2007, Gallery 1.7 will be released and it will likely be the last actively developed version in the Gallery 1.x series to be released. After Gallery 1.7 is released the developers are expected to support it for one year which gives procrastinators the time the need to finally adopt Gallery 2.