He is best known for his 1975 and 1977 work on the longest common subsequence problem: Hirschberg's algorithm for this problem and for the related string edit distance problem solves it efficiently in only linear space. He is also known for his work in several other areas, including Distributed Algorithms.
His notable achievements include his work in 1975 and 1977 on the longest common subsequence problem, where Hirschberg's algorithm provides an efficient solution using only linear space. Additionally, he has made significant contributions to areas such as Distributed Algorithms.