Application compartmentalisation decomposes software into sandboxed components in order to mitigate security vulnerabilities, and has proven effective in limiting the impact of compromise. However, experience has shown that adapting existing C-language software is difficult, often leading to problems with correctness, performance, complexity, and most critically, security. Security-Oriented Analysis of Application Programs (SOAAP) is an in-progress research project into new semi-automated techniques to support compartmentalisation. SOAAP employs a variety of static and dynamic approaches, driven by source code annotations termed compartmentalisation hypotheses, to help programmers evaluate strategies for compartmentalising existing software.