LZ1 (also LZ77, from its year of creation), a lossless data compression algorithm
Universal source coding, a data compression method that asymptotically approaches the data compression ratio of the optimal data compression method, e.g., LZ77 and LZ78
The LZ77 and LZ78 algorithms authored by Lempel and Jacob Ziv have led to a number of derivative works, including the Lempel–Ziv–Welch algorithm, used in the GIF image format, and the Lempel-Ziv-Markov chain algorithm, used in the 7-Zip and xz compressors.
In 1977 and 1978, Jacob Ziv and Abraham Lempel published a pair of papers on a new class of lossless data-compression algorithms, now collectively referred to as LZ77 and LZ78.