This is one of my favourite pieces of accessibility software. Granted it is technically not designed to be accessibility software but I use it in most games to make them easier for me to play. PIE stands for Programmable Input Emulator and the glove is because it was originally designed to be used with virtual reality gloves.
GlovePIE can be used to emulate a variety of different input devices including keyboards, mice, joysticks and gamepads. It can even be used to add rudimentary voice commands to some games. You can also use it to make macro type buttons for complicated keypresses for games such as Mortal Kombat I like to use it because it allows me to easily remap keys. Lots of times when I am playing a game and the right mouse button does nothing I tend to remap it to a function on the game. This is really useful when you are playing a game that does not have customisable controls built in.
Most of the time when I am playing a game I will use GlovePIE for its ability to allow me to remap keys although I have been known to make a few macro functions aswell. When I first started experimenting with speech recognition I liked to use this program to add voice commands to my game. I would mainly use the voice commands to and perform actions that don't really require quick reflexes, such as weapon selection, inventory navigation and action buttons like "open door". This worked well for a while and only when you had few voice commands but once you add too many this system started to get confused. It also required windows speech recognition and this is one of the reasons why in a previous post I recommended that you train that as well just in case. I have since discovered better ways to add voice recognition but regardless GlovePIE is a very good tool to add a bit of much-needed accessibility to some games. Now it is probably more useful for older games seeing as a lot of new games already have customisable configurations. It still has its use for macros though in all games where you might need them. I would highly recommend you give this a go before you decide to splash out on more expensive stuff.
You can download GlovePIE from this link: