René Just

Assistant Professor

College of Information and Computer Sciences
University of Massachusetts Amherst

140 Governors Drive
CS 358
(413) 545-0379


I am interested in software engineering and software security, in particular static and dynamic program analysis, mobile security, mutation analysis, type systems, and mining software repositories.

Current Research Projects

A Database of Existing Faults to Enable Controlled Testing Studies for Java

Defects4J is a database and extensible framework that provides 357 real bugs from 5 real-world open source programs. Each real bug comes with a comprehensive test suite of which at least one test case can expose that bug.
Defects4J provides easy access to faulty and fixed program versions. Defects4J also features a test execution framework, which provides a high-level interface to common tasks in software testing research, making it easy to conduct and reproduce empirical studies.

Major mutation framework:
Efficient and scalable mutation analysis for Java programs

The Major mutation framework enables fundamental research on mutation analysis as well as efficient mutation analysis of large software systems. The framework provides the following three components:
  1. Compiler-integrated mutator
  2. Mutation analyzer for JUnit tests
  3. Domain specific language to configure the mutation process in detail

Static Program Analysis for Reliable Trusted Apps

The goal of the SPARTA project is to statically verify the absence of information-flow malware in mobile applications. The technical centerpiece of this approach is an information-flow type system and a corresponding type-checker that verifies information-flow properties specified in a high-level policy.