BitTorrent is a tool for copying files from one machine to another. FTP punishes sites for being popular. Since all uploading is done from one place, a popular site needs big iron and big bandwidth. With BitTorrent, clients automatically mirror files they download, making the publisher's burden almost nothing.
Launch4j is a cross-platform tool for wrapping Java applications distributed as jars in Windows native executables. The executable can be configured to search for a certain JRE version or use a bundled one, and it's possible to set runtime options, like the initial/max heap size. The wrapper also provides better user experience through an application icon, a native pre-JRE splash screen, and a Java download page in case the appropriate JRE cannot be found. The increase in size of the application is small.
bitstring is a Python module that helps to make the creation and analysis of binary data as simple and natural as possible. Objects can be constructed from integers (big and little endian), floats, hex, octal, binary, byte data, iterables, or files. They can be sliced, joined, reversed, packed, unpacked, inserted into, overwritten, and otherwise operated upon with simple functions or slice notation. They can also be parsed, searched, and navigated in, similar to a file or stream. Internally the data is efficiently stored as byte arrays. It is available for Python 2.6 and later (including Python 3).