POSIX amake is a software build tool that adds automatic dependency analysis and target caching to GNU Make. It monitors and records commands executed, programs executed, shared libraries opened, files accessed, and environment-variable values. It maintains a multiuser/multihost cache of previously built targets: an SQL database stores target metadata (e.g., command and dependency checksums), while a regular filesystem stores target files and their siblings. The target-cache feature is optional, being enabled by a makefile variable. It has been used to build and rebuild the Linux kernel.