Release Notes: A new "Explain this decision" feature lets you find out why a particular version isn't being selected. There is a new "POSIX" architecture group for implementations which work everywhere except on Windows. The certifi library can be used to provide the trusted CA list on platforms without a system list. Connections are now queued to avoid overloading sites with too many at once. The user's preferred terminal emulator is now used, instead of hard-coding xterm.
Release Notes: More code has been migrated from Python to OCaml. The logic for handling mirrors has been improved. The cache explorer now works when the cache is larger than 2GB.
Release Notes: Around half of the code has now been migrated to OCaml, making many functions around 10x faster. Local feeds can now specify local archive files. Tab completion was added for the 0launch command.
Release Notes: An optional OCaml frontend allows faster startup. Tab completion now supports the Fish shell. Archive references in local feeds can now reference local files, not just remote URLs. Various minor bugs were fixed.
Release Notes: Bugs with HTTP chunked transfers on Python 3 and with the new <file> support producing empty files were fixed. The mirror service is no longer called if a download is slow because it is queued or waiting for user interaction. The desktop launcher is now a single item, making it easier to use from Unity and GNOME 3. Performance has been improved when running apps, especially on Arch Linux.
Release Notes: A new search feature makes it easier to search for available software. 0install now works with win-bash, simplifying creation of cross-platform source releases. Download recipes can fetch individual files, not just archives (useful for, for example, jar files). The Tulip Python mainloop can be used if GObject isn't available. XZ compression is now supported in .deb archives.