* Add new platform abstraction (252)
* Add Null POSIX backend
* Add support for eventfd
* Add support for thread IDs on Haiku, NetBSD and Solaris
* New API libusb_hotplug_get_user_data()
* Darwin (macOS): Fix race condition that results in segmentation fault (701)
* Darwin (macOS): Fix stale descriptor information post reset (733)
* Darwin (macOS): use IOUSBDevice as darwin_device_class explicitly (693)
* Linux: Drop support for kernel older than 2.6.32
* Linux: Provide an event thread name (689)
* Linux: Wait until all URBs have been reaped before freeing them (607)
* NetBSD: Recognize device timeouts (710)
* OpenBSD: Allow opening ugen devices multiple times (763)
* OpenBSD: Support libusb_get_port_number() (764)
* SunOS: Fix a memory leak (756)
* SunOS: Various fixes (627, 628, 629)
* Windows: Add Visual Studio 2019 support
* Windows: Drop support for WinCE and Visual Studio older than 2013
* Windows: Drop support for Windows XP
* Windows: Support building all examples using Visual Studio (151)
* Documentation fixes and improvements
* Various other bug fixes and improvements