The retail giant’s cloud-computing arm, Amazon Web Services, bought a small startup called Cloud9 that specializes in software development tools. Cloud9 revealed the deal on Thursday, but did not disclose how much the deal was worth.

Cloud9 is based in both Amsterdam and San Francisco and has under 50 employees, according to the startup’s LinkedIn profile. The startup built a so-called integrated development environment, which is basically an-all-in-one software package that gives coders a bunch of tools to build, test, debug, and run their own software.

It’s unclear whether Amazon (AMZN) is acquiring the startup for its workforce or if it will incorporate some of its technology within its own cloud computing service.

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The startup counts Salesforce (CRM), business software company Atlassian (TEAM), and music service Soundcloud as customers.

“We’re excited to let you, our users and customers, be among the first to learn that we have been acquired by Amazon!” wrote Cloud9 CEO Ruben Daniels in a blog post. “We will be joining the Amazon Web Services family, and we’re looking forward to working together on terrific customer offerings for the future.”

In January, Cloud9 said that it would then allow its customers to use its technology to build apps on Google’s (GOOG) competing cloud computing service. It’s unclear how Cloud9’s deal with Amazon will affect that capability.

Amazon declined to comment on the deal.

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In April, Amazon bought for an undisclosed price a Silicon Valley startup called Orbeus that specializes in image-recognition technology.