SAGE (Scalable Automated Guided Execution) is a hybrid fuzzer developed at Microsoft Research. It has been used extensively since 2007 for testing Microsoft software.
It is a whitebox fuzzer, in the sense that it uses the source code of a program to dynamically generate test cases.
Patrice Godefroid, Michael Y. Levin, and David Molnar. 2012. SAGE: Whitebox Fuzzing for Security Testing. Queue 10, 1 (January 2012), 20–27. https://doi.org/10.1145/2090147.2094081 [pdf]
@article{10.1145/2090147.2094081,
author = {Godefroid, Patrice and Levin, Michael Y. and Molnar, David},
title = {SAGE: Whitebox Fuzzing for Security Testing: SAGE Has Had a Remarkable Impact at Microsoft.},
year = {2012},
issue_date = {January 2012},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
volume = {10},
number = {1},
issn = {1542-7730},
url = {https://doi.org/10.1145/2090147.2094081},
doi = {10.1145/2090147.2094081},
journal = {Queue},
month = {jan},
pages = {20–27},
numpages = {8}
}