There are 5 emulators currently listed for Java-enabled systems:
- Hob v0.9.2
 Emulates: 48K ZX Spectrum.
 Tape/Disk Formats: .sna and .z80
 Requirements: Java-enabled browser (v1.1+).
 Created by: Nigel Barford.
 Last updated: April 11th, 2003
 Comments: Also emulates the Cursor Joystick Interface. Variable window size, 40 games playable online, with a small collection available for download.
- Jasper v1.1
 Emulates: 48K ZX Spectrum.
 Tape/Disk Formats: .sna and .z80
 Requirements: Java-enabled browser (v1.02+).
 Created by: Adam Davidson & Andrew Pollard.
 Last updated: April 27th, 1997
 Comments: Around 30 games are available to play online. Source code is available. Send comments to the authors.
- JX-Speccy v1.4
 Emulates: 48K / 128K ZX Spectrums.
 Tape/Disk Formats: .z80
 Requirements: Java-enabled browser.
 Created by: Marzio De Biasi.
 Last updated: February 17th, 2002
- JZX
 Emulates: 48K / 128K ZX Spectrums.
 Tape/Disk Formats: .z80
 Requirements: Java-enabled browser.
 Created by: Razvan Surdulescu.
 Last updated: October 8th, 2001
 Comments: Source code and documentation is available for offline use.
 
- ZZ Spectrum v1.4
 Emulates: 16K / 48K / 128K ZX Spectrums.
 Tape/Disk Formats: .sna, .zx, .z80 and .tap files.
 Requirements: Java-enabled browser.
 Created by: Troels Noergaard.
 Last updated: January 31st, 2001
 Comments: Also emulates the Kempston, Sinclair and Cursor Joystick Interfaces, and the ZX Interface I with one Microdrive. Sound is available if you have the JSyn plug-in from Softsynth (see web site).