ZAP (https://www.owasp.org/index.php/OWASP_Zed_Attack_Proxy_Project) evolved from Paro, and was developed by the OWASP project. It is very similar to Burp Suite; however, personally, I think Burp Suite has better options and functions than Zap, but it is an important option to consider during bug bounty hunting.

It has tools, such as a repeater, intruder, fuzzer, and a vulnerability analysis tool, as shown in the following screenshot: