Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
GNU Make - GNU Make is a tool which controls the generation of executables and other non-source files of a program from the program's source files.
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
SCons - SCons is an Open Source software construction tool—that is, a next-generation build tool.
Bitrise - Tens of thousands of agencies, startups and enterprise companies with mobile apps - including Runkeeper, Grindr, Duolingo and more - use Bitrise to automate their way to increased productivity & speed
SBT - SBT is a build tool for Scala, like Ant or Maven but with hieroglyphics.