Fiddler
Free
Fiddler is an HTTP debugging proxy server application.
mitmproxy
Open Source
mitmproxy is an interactive TLS-capable intercepting HTTP proxy for penetration testers and software developers.
Charles
Commercial
Charles is an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic.
Zed Attack Proxy
Open Source
Zed Attack Proxy (ZAP) is a tool to find security vulnerabilities in web applications.
Compare Burp Proxy with alternatives
Compare mitmproxy and Burp Proxy and decide which is most suitable for you.
Compare Zed Attack Proxy and Burp Proxy and decide which is most suitable for you.