You could have downloaded IMROMPTU 2.5 for Mac from our software library for free. This free Mac application is an intellectual property of moso. The most frequent installer filename for the application is: impromptu_2.5.dmg. The program lies within Developer Tools, more precisely IDE. The most popular version of the software is 2.5.
From the developer:
IMROMPTU is an OSX programming language and environment for composers, sound artists, VJ's and graphic artists with an interest in live or interactive programming. Impromptu is a Scheme language environment, a member of the Lisp family of languages. Impromptu is used by artist-programmers in livecoding performances around the globe.
You may want to check out more Mac applications, such as PowerGlot, ChIDE or flex sdk 3, which might be similar to IMROMPTU.