In your browser
MacBeeb
MacBeeb's own BBC Micro, compiled to WebAssembly. Click the screen and type: it's a Model B with BASIC and a disc drive, and it doesn't send anything anywhere.
Click a screen to type on that BBC's keyboard. F12 is Break, End is COPY. Keys:
Discs
An .ssd or .dsd for the Model B, ADFS too for the Master: choose one, or drop it on the screen. It stays in this tab.
Type and save
Paste a program in, and the BBC types it for you.
Sound and joysticks
No gamepads: connect one and press a button to use it as the BBC's joystick.
Econet
With Econet on, every BBC here gets an Econet module (and its network filing system: DNFS on a Model B, ANFS on a Master) and they share one network, run in step as MacBeeb runs them.
"Add a file server" adds a BBC with Acorn's Level 1 file server in its drive: start it there with
CH."FS" and answer its questions.
Econet over the Internet
Join a room on an Internet Econet service, and the stations here talk to other people's, in MacBeeb or in a browser.
ROMs
The BBCs start with the ROMs MacBeeb has (Acorn's). To use others, choose them here: they stay in this browser and are never uploaded.
Performance
This is MacBeeb's emulation, the same Swift, compiled to WebAssembly. The Mac app has much more: the B+, Compact and second processors, the Game Library, the debugger, the Network Studio. More about MacBeeb.