Schwartz is the co-author of several widely used books about Perl, a programming language, and has written regular columns about Perl for several computer magazines, including UNIX Review, Web Techniques, and the Perl Journal. He popularized the Just another Perl hacker signature programs. He is a founding board member of the Perl Mongers, the worldwide Perl grassroots advocacy organization. He was a member of the Squeak Oversight Board, which oversees the Squeak programming language.
Schwartz's name is also associated with the Schwartzian transform, an algorithm to efficiently sort a list according to a computation, without repeating the computation many times for each element of the list. He also originated the name spaceship operator for use in his teaching, because it reminded him of the spaceship in an HP BASIC Star Trek game.
Schwartz is an influential member of the F/OSS community, and has been named a "Perl Expert" and interviewed by numerous outlets – to discuss his views on Perl, Ruby, Smalltalk and other topics – including Dr. Dobb's, Paul dot Com Security TV, The Command Line, PerlCast, FLOSS Weekly, ONLamp.com, and InfoQ. Schwartz was also a speaker at the 2011 OSCON conference and a keynote speaker at the 2010 Texas LinuxFest conference.
His various books have been met with positive reviews.
In July 1995, Schwartz was prosecuted in the case of State of Oregon vs. Randal Schwartz, which dealt with compromised computer security during his time as a system administrator for Intel. In the process of performing penetration testing, he cracked a number of passwords on Intel's systems. Schwartz was originally convicted on three felony counts, with one reduced to a misdemeanor, but on February 1, 2007 his arrest and conviction records were sealed through an official expungement and he is legally no longer a felon.