NestedVM was another early attempt (2004) to run C, C++, Fortran, etc. on the JVM, but at substantial performance degradation. This was a clever hack that ran a Java coded MIPS emulator and loaded a compiled binary into a large array. Performance was 20-40% of native speed, but still fast enough for some applications, such as SQLite as a JDBC driver.
Website, source repo, and paper seem to still be available, try archive.org for dead links: