TCP over IP as a protocol is an “open standard”. Network implementations are nearly always strictly proprietary.
The “protocols” behind browsers are public. HTML, CSS, and ECMAScript are all well defined on sites like the Mozilla documentation. You are free to implement your own browser that follows these standards.
Browsers should be open standards, like TCP/IP.
TCP over IP as a protocol is an “open standard”. Network implementations are nearly always strictly proprietary.
The “protocols” behind browsers are public. HTML, CSS, and ECMAScript are all well defined on sites like the Mozilla documentation. You are free to implement your own browser that follows these standards.