Contiki, an actively-developed IOT OS, supports 6502-based hardware, including the Apple ][e, Atari XLs, and the Commodore 64. Among other useful applications,

Contiki, an actively-developed IOT OS, supports 6502-based hardware, including the Apple ][e, Atari XLs, and the Commodore 64. Among other useful applications, it has an http server, email client, an irc client, a web browser, a desktop GUI, and a VNC. The Apple //c is already pretty close to a laptop, and can be turned into a laptop with Apple's the flat panel display and third-party batteries. If laptop-ifying a desktop is okay, there are people who have turned Atari XLs and Commodore 64s into laptops. For all of these ancient computers, you can easily buy or build ethernet (or, more recently, esp8266-based wifi!) adapters. The biggest catch that I know of is that you would need a newer computer to periodically build and flash updates. Contiki is not self-hosting.