Andrew Appel is the son of mathematician Kenneth Appel, who proved the Four-Color Theorem in 1976.[2] Appel graduated summa cum laude with an A.B. in physics from Princeton University in 1981 after completing a senior thesis, titled "Investigation of galaxy clustering using an asymptotically fast N-body algorithm", under the supervision of Nobel laureate James Peebles.[3] He later received a Ph.D. (computer science) at Carnegie Mellon University, in 1985.[4] He became an ACM Fellow in 1998, due to his research of programming languages and compilers.[5]
Andrew Appel campaigns on issues related to the interaction of law and computer technology. He testified in the penalty phase of the Microsoft antitrust case in 2002.[7] He is opposed to the introduction of some computerized voting machines, which he deemed untrustworthy.[8] In 2007, he received attention when he purchased a number of voting machines for the purpose of investigating their security.[9] In 2024, he testified as an expert on voting machines in federal court hearings that led to a preliminary injunction disallowing New Jersey’s “county line” system that was alleged to provide an unfair advantage to candidates backed by county political party organizations.[10]