Floating IPS is a patcher for IPS and BPS files, aiming for a simple interface yet plenty of power under the hood.

Features:

• Creates the smallest BPS patches of any known tool in existence, and is faster than any other comparable creator
• Creates the smallest IPS patches of any known tool in existence, too (but only a little smaller, Lunar IPS is quite good)
• Fully-featured GUIs under Windows and GTK+, including command line support; can also be a pure command line program
• Can apply multiple patches to the same ROM, creating a huge pile of ROMs (GUI only)
• Remembers which ROMs you've used, and will use them again if it thinks it's correct (BPS only, GUI only)
• Can launch other programs after patching the ROMs, allowing you to double click a BPS to launch an emulator (GUI only)

Planned:

• Automatically enable ROM guesser (open a message box the first time it guesses a ROM, asking if you want that)
• Different emulators for different filetypes (check the extension, or default to the OS default handler?)
• Better support for ROM database in CLI; the -d flag, or DB enabling from the GUI (for pure-CLI, existence of flipsdb.bin file beside Flips), will store ROMs in the database; the filename "." will read from it, and "wrong ROM" will look for the right one (but not automatically use it)
• Use path of patch as output filename, not the ROM path
• Better autodetection for command line; if the first two files have same extension, create, else apply

Not planned (if your plans are different, send a PR):

• OSX GUI support; there's a third-party fork here, and MultiPatch exists and the Windows version works in Wine. I can't test OSX stuff well enough to merge that fork, so pick your favorite.
• Qt GUI support; my distro prefers GTK+, and all distros I've seen can run both GTK+ and Qt, not worth the effort (and QString's UTF-16 irritates me)

To compile (Linux):

• Install g++ and build-essential (names may vary on non-Debian-based distros). If you want a GUI, install libgtk-3-dev and pkg-config as well.
• To build an optimized binary, use ./make.sh; for development, use make CFLAGS=-g

To compile (other Unix):

• Install make and a C++ compiler, then use make CXX=clang++ CFLAGS=-O3 (may require GNU make, not tested; ./make.sh may work, not tested)

To compile (Windows):

• Install mingw-w64
• mingw32-make CFLAGS=-O3
• Alternatively, here's a binary.