"Programs written by individual hackers tend to follow the scratch-an-itch model. These programs will solve the problem that the hacker, himself, is having without necessarily handling related parts of the problem which would make the program more useful to others. Furthermore, the program is sure to work on that lone hacker's own setup, but may not be portable to other Scheme implementations or to the same Scheme implementation on other platforms. Documentation may be lacking. Being essentially a project done in the hacker's copious free time, the program is liable to suffer should real-life responsibilities intrude on the hacker. As Olin Shivers noted, this means that these one-man-band projects tend to solve eighty-percent of the problem."
