Downloading libusbx 1.0.18 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. This free software for Mac OS X was originally created by libusb. The application belongs to Developer Tools. We recommend checking the downloaded files with any free antivirus.
From the developer:
libusb is a C library that provides generic access to USB devices. It is intended to be used by developers to facilitate the production of applications that communicate with USB hardware. It is user-mode: No special privilege or elevation is required for the application to communicate with a device.
You may want to check out more software for Mac, such as Objective Basic, Pleinpot or Epsilon, which might be similar to libusbx.