Adobe, Bloomberg, HP, Huawei and Salesforce are backing the Linux Foundation as it seeks a security audit for OpenSSL, the security protocol exploited in the Heartbleed bug.
According to the foundation its backers will provide $3.6m over the next three years, helping to pay for two developers to work on OpenSSL, and an audit to be conducted by the Open Crypto Audit Project, the non-profit responsible for reviewing TrueCrypt.
Parker Harris, co-founder of Salesforce, said: "Open source software has fuelled the advancements we've seen over the last decade in cloud and mobile computing.
"That is why supporting the Linux Foundation's Core Infrastructure Initiative is an absolute necessity in today's software industry, and salesforce.com is delighted to contribute to this effort and foster the next generation of open source computing innovation."
The revelation that OpenSSL was vulnerable to what became known as Heartbleed discredited many tech giants reliant on the technology, with Facebook, Google and Yahoo all affected by the security flaw.
However the move by the five major companies indicates a resurgence of support for open-source technology, with the firms joining Amazon, Facebook, Google, IBM and Microsoft in backing the foundation, each contributing $100,000 per year.
Aside from OpenSSL the initiative will also work on the Network Time Protocol, which handles clock synchronisation, and OpenSSH, encrypted communications software.
Jim Zemlin, executive director of the Linux Foundation, said: "Our global economy is built on top of many open source projects. Just as The Linux Foundation has funded Linus Torvalds to be able to focus 100% on Linux development, we will now be able to support additional developers and maintainers to work full-time supporting other essential open source projects."