zbackup is a globally-deduplicating backup tool, based on the ideas found in rsync. Feed a large .tar into it, and it will store duplicate regions of it only once, then compress and optionally encrypt the result. Feed another .tar file, and it will also re-use any data found in any previous backups. This way only new changes are stored, and as long as the files are not very different, the amount of storage required is very low.
Any of the backup files stored previously can be read back in full at any time. The program is format-agnostic, so you can feed virtually any files to it (any types of archives, proprietary formats, even raw disk images…)
Attic is a deduplicating backup program written in Python. The main goal of Attic is to provide an efficient and secure way to backup data. The data deduplication technique used makes Attic suitable for daily backups since only the changes are stored.
SiteSucker is a Macintosh application that automatically downloads Web sites from the Internet. It does this by asynchronously copying the site’s Web pages, images, backgrounds, movies, and other files to your local hard drive, duplicating the site’s directory structure. Just enter a URL (Uniform Resource Locator), press return, and SiteSucker can download an entire Web site.
Larch is a tool to copy messages from one IMAP server to another quickly and safely. It’s smart enough not to copy messages that already exist on the destination and robust enough to deal with interruptions caused by flaky connections or misbehaving servers.
Larch is particularly well-suited for copying email to, from, or between Gmail accounts.
Powerful archiving and search for Twitter and App.net. Watermark doesn’t just keep your own tweets and favorites forever — it stores every tweet and App.net post from everyone you are following, so you can find what you need no matter who posted it.
$3.99 a month, with archive access via the web or an iOS app.
…a collection of utilities dealing with Tumblr blogs.
tumble.py creates new posts from RSS or Atom feeds
tumblr_backup.py makes a local backup of posts and images
mail_export.py mails tagged links to a recipient list
delicious_import.py imports delicious.com links into Tumblr
More on tumblr_backup.py:
The backup includes all images from photo and photoset posts. An index links to monthly pages, which contain all the posts from the respective month with links to single post pages. Command line options select which posts to backup and set the output format.
By default, all posts of a blog are backed up in minimally styled HTML.