Microsoft has produced a version of its database software that runs on the rival Linux operating system.
The version of SQL Server software it has made for Linux will be released in mid-2017, it said in a blogpost.
The creation of the software is a significant step for Microsoft which has traditionally focused on its core Windows operating system.
It is one of several steps it has taken to open up its software to rivals under boss Satya Nadella.
Microsoft's SQL Server is one of the company's core products and the Windows version is used by many customers to run and manage databases.
Scott Guthrie, head of Microsoft's cloud and enterprise group, said the Linux version was currently being previewed and tested by customers but would be fully available by the middle of next year. He said Renault's Formula 1 racing team was one of the first test customers for the code.
Microsoft has about a 21% share of the database software market, suggest figures from analyst firm Gartner.
Oracle is the market leader and the release of SQL Server for Linux will help Microsoft compete with that company, it said.
Gartner analyst Merv Adrian told Reuters that the move made sense because although business spending on technology had been "lacklustre" the amount of cash firms spent to maintain and update database software had kept rising.
Mr Adrian said Oracle would undoubtedly notice Microsoft's step into the Linux market.
"It's a significant competitive threat they didn't have before," he said.
The move also puts Microsoft into more direct competition with IBM and SAP. There are also a lot of free Linux-based database programs available.
The release of SQL Server is one among several steps Microsoft has taken to work more closely with Linux and its advocates.
The data centre management software Microsoft uses for its Azure service is based on Linux; it has also produced software that helps people manage Linux servers and has released an analytics package called R Server that works with several different versions of Linux.
The greater willingness to work with former rivals has been one of the hallmarks of boss Satya Nadella's reign at Microsoft. Mr Nadella took over as chief executive in February 2014.