Cryptocurrency exchange Kraken has donated $150,000 in bitcoin to BTCPay Foundation, the entity managing BTCPay, a popular open-source tool for merchants accepting bitcoin payments.

Since BTCPay is free, it relies on donations like Kraken's to run and to fund developers making improvements to the app. BTCPay is a tool for bitcoin bookkeeping tasks that merchants need, such as managing invoices tracking how much bitcoin the merchant is owed for each product sold.

"This is the largest donation in BTCPay Foundation’s history, speaking to the value and importance that we place on making it easy for people to acquire Bitcoin and other cryptocurrencies," a spokesperson for San Francisco-based Kraken said. (BTCPay Foundation confirmed that Kraken's donation was indeed its largest.)

BTCPay Foundation is also supported financially by Square Crypto, OKCoin and several other bitcoin companies.

"BTCPay provides a crucial invoicing solution for anyone who wants to receive bitcoin, whether its fundraising for a nonprofit or for receiving e-commerce payments. We’re excited to help the team grow their offering," the spokesperson added.

Read more: BTCPay Looks to Anonymize Bitcoin Transactions With PayJoin Integration

Kraken's donation is a part of a recent uptick in organizations donating to open-source bitcoin development. In the last couple of weeks, the Human Rights Foundation announced it will be funding a developer working on improving bitcoin's privacy, and crypto exchanges OKCoin and BitMEX announced that they are partnering to sponsor Bitcoin Core contributor Amiti Uttarwar.

Open-source projects, while generally not lucrative because they are free for anyone to use, are a foundational component of bitcoin and other cryptocurrencies. Bitcoin's underlying code is open source, meaning anyone can view it or potentially make changes to it. 

Developers have traditionally tinkered with such projects in their spare time. But more are beginning to get paid for their work because of how important these projects are to the ecosystem.

“The success of open-source ecosystems like Linux and now Bitcoin is proof that deploying and investing in open source solutions makes business sense. Companies can then build products that leverage these open source platforms,” Kraken bitcoin strategist Pierre Rochard stated in an email to CoinDesk.