Developer collaboration services are back on investors’ agenda. Two months after leading a $1.5 million round into GitLab Inc., Khosla Ventures is coming back for more and pouring an additional $4 million into the startup’s coffers to help ramp its battle against the better-known and better-funded competition.

GitLab is not the typical tech underdog. The Netherlands-based outfit has a small staff and boasts little brand awareness beyond its immediate ecosystem, but possesses something few of its fellow up-and-comers can claim: a well-established user base. Its namesake open-source Git repository management tool is used at over 100,000 organizations around the world.

The list includes the likes of AT&T Inc., Alibaba Group Holding Limited and Elon Musk’s Space Exploration Technologies Corporation (better-known as SpaceX), among other household names. That impressive adoption can be credited to a compelling feature set, and, perhaps even more importantly, an open-source business model that goes much further than most.

GitLab has made the system powering its repository management software freely accessible for anyone to download and implement on their own infrastructure, whether it’s private hardware or, more likely with development teams, a virtual machine on one of the major cloud platforms. The startup commercializes the technology with a paid hosted service that adds premium features for large organizations.

Much of the new $4 million in funding will go towards trying to upsell that paid edition to existing free users and winning over more of them from arch-nemesis GitHub. The rest will be used to accelerate the development of the core open-source version, which is already advancing at a breakneck rate.

The next major version of GitLab is due to launch next week with new continuous integration features for fast-moving development teams, an improved interface and a 50 percent reduction in disk usage. The release embodies the combined efforts of the startup’s modest engineering team and the surrounding community of more than 800 outside contributors.

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