Here you can learn where to find midi companies on the web
There are over 250 companies around the world making products that support MIDI — well known companies such as Apple and Microsoft, Roland and Yamaha, Nokia and Sony/Ericsson, and others.
Most film and TV scores, as well as much popular recorded music is written and performed using electronic keyboards and other MIDI-equipped musical instruments. (Thanks to advances in digital sampling and synthesis technologies, the orchestra playing behind that big-screen block buster is more likely to be the product of MIDI than a real orchestra with dozens of acoustic instruments.)
MIDI also has many other interesting and popular uses. For example, MIDI Show Control is a command and control language used with rides at major theme parks and events at Las Vegas casinos, and MIDI Machine Control is used in recording studios to synchronize and remotely control recording equipment.