The original Apple II shipped in June 1977 and the last one — the IIgs ROM 3 — came off the line in late 1992. Sixteen years in production. Nothing else in the home computer era had that kind of run, and most of it came down to one thing: Woz published the schematics.

Apple shipped the reference manual for the II with actual circuit diagrams and a complete description of the ROM. Cloning, extending, and learning from the design was possible from day one. That openness is why the Apple II ended up in schools, why it stayed in schools for a decade longer than it should have, and why the community documenting every quirk of it is still active now.

Two tracks inside the Apple II family:

• Apple 2 — the 8-bit line: II, II+, IIe, IIc, IIc Plus. MOS 6502 or 65C02 at 1 MHz, text and hi-res color graphics, the machine that ran VisiCalc, Wizardry, Ultima, and thousands of others.
• Apple 2 GS — the 16-bit evolution from 1986. 65C816 CPU, color graphics at 640×200, Ensoniq DOC 32-oscillator wavetable synth, and a desktop GUI in GS/OS.

The family shares a lot more than the number in the name. IIgs boots the 8-bit ROM and runs almost any II or IIe software. The IIe Platinum keyboard is the same layout as the IIgs's. ProDOS and DOS 3.3 disks pass between machines without fuss.

The community's strengths:

• The original documentation is still online — Beagle Bros manuals, Apple reference material, and disassembled ROMs
• Modern storage is mature: CFFA3000, Floppy Emu, and BMOW's BOOTI card cover every use case
• New software still ships — cc65 is the standard cross-compiler, Merlin is still around for assembly on original hardware, and game releases happen a few times a year

Pick a track above. If you're new, the 8-bit IIe is the most forgiving entry point — cheap, well-documented, strong software catalog. The IIgs is rarer, more expensive, but gives you color and music that the rest of the line can't. Emulation: AppleWin on Windows, Virtual II on Mac, or MAME. The Apple II forum is the default destination for both tracks.