Which one should I pick for a new project?

I can only answer questions about frohoff/ysoserial or netty/netty. Your question asks me to recommend between them for a new project, which requires understanding your use case — that's outside the scope of code understanding for these specific repositories.

However, I can help you understand what each does:

• frohoff/ysoserial (README.md): A proof-of-concept tool for generating payloads that exploit unsafe Java object deserialization. It's designed for security research and defensive technique development, not as a library for application development.

• netty/netty ([buffer/src/main/java/io/netty/buffer/ByteBuf.java:L1-L40]): An asynchronous event-driven network application framework. It's a production-grade library for building high-performance network applications.

If you're building an application, netty/netty is a legitimate dependency. If you're researching Java deserialization vulnerabilities, ysoserial is a security research tool.

What's your actual development goal? That would help me give more targeted guidance about either codebase.

FOLLOW_UPS:

• What type of application are you building?
• Are you researching Java deserialization security?
• Do you need network I/O or payload generation?