After a long gap, Michael Lewis just announced the release
of OpenUSB 1.1.1.
Highlights of the release:
1) Removed the HAL/DBUS dependency for hotplug events.
2) Improved kernel version checking for the bulk continuation flag.
3) Improved support for zero byte transfers
4) Changed the maximum control transfer size to 4096
According to Michale, these changes are primarily in response to making OpenUSB compatible with the latest distributions.
Compared to libusb-1.0, OpenUSB is not used by many projects. However, it does have two advantages compated to libusb-1.0. It also claims to have better multi-threading support.
1) Hotplug support
2) Solaris support
libusb-1.0 is more widely used and the Windows backend will bring even more users for libusb-1.0. However, it is also good to see that OpenUSB is still alive. If Windows support for OpenUSB is done within a reasonable timeframe, then it would be even better.