IP65 consists of three parts

• A TCP/IP library to be used by 6502 asm programmers using the ca65 macro assembler.
• A TCP/IP library to be used by C programmers using the cc65 6502 C cross compiler.
• Some ready-to-run TCP/IP programs using the TCP/IP library.

All three parts are available for three 6502 based targets

• The C64
• The Apple II
• The ATARI (XL)

IP65 requires Ethernet hardware. There's no support for TCP/IP over serial connections whatsoever.

On the C64 there are two supported Ethernet carts

• The RR-Net - emulated by VICE
• The ETH64

On the Apple II there are three supported Ethernet cards

• The Uthernet - emulated by AppleWin and GSport
• The LANceGS
• The Uthernet II

On the ATARI (XL) there is one supported Ethernet cart

• The Dragon Cart - emulated by Altirra