Nettle is the terminal emulator and telnet client for the RISC OS operating system. It utilises the ZapRedraw module for speedy display and is a fast, clean native implementation.

Nettle supports most common terminal types, including vt100, vt102, vt220 and xterm terminal emulation in full colour, along with some more exotic features which you might not expect from a terminal emulation program, such as URL launching - just double click on any URL that is displayed in a Nettle window and it will launch in to your browser. Nettle also has an ANSI Task task window feature, which allows unix programs such as ssh, lynx, BitchX, ncftp2 and nano with ANSI terminal interfaces to be run natively on RISC OS for the first time.

Example Nettle screenshot showing ANSI colouring
(A tiny font size was selected just for this webpage screenshot!)

Beta release:
April 11th 2010


Source code


Latest release:
April 4th 2004


Source code


Previous releases:
0.2040r - 07/12/2003 (src)
0.2032r - 07/12/2002 (src)
0.2020r - 20/02/2002 (src)
0.2010r - 16/09/2001 (src)
0.2000r - 01/09/2001 (src)

Also required if not using Select 2,3 or Adjust:
Mailing lists


Useful links
Developers page
CVS Interface
Latest !Help
(includes bug/todo list)

Unix Porting project
Ports of UNIX programs, for RISC OS


Nettle was started by Alex Macfarlane Smith, initially writing a very well featured version of Nettle in BBC BASIC. Unfortunately, this was rather too slow to be really useful, so after some encouragement, the move was made to a C-language based development. This is when the other developers started work.

Nettle is built with the StubsG C libraries, to allow it to run unmodified on both 26bit and 32bit RISC OS variants. Development is mostly done on the latest release of RISC OS Select but we support everything from RISC OS 3.1 through to RISC OS 5 running Internet module verison 4.xx or 5.xx. Nettle is also supported and tested with VirtualRiscPC-SE. If you're not running Select 2,3 or Adjust then you'll also need the SocketWatch module.

Opensource development is managed via SourceForge - please submit any patches and bug reports via that system, or email


A full historical changelog can be gleaned from cvs, but here is the digest version, taken from the !Help file:

0.2042r : April 4th 2004
    New Features:
      German messages (credit Stefan Bellon)
      True probing detection of Internet pollword capability
      Better internal internationalisation handling
    Bugs fixed:
      Tabs are included in non-raw spool files
      Cope cleanly when no Internet module is present
0.2040r : December 7th 2003
    New Features:
      Updated to 32bit build. Runs on 26bit and 32bit RISC OS.
      Added "Reconnect" menu item to reconnect dead sessions
      Sprites11 highres icons added
      Local terminal Options setting (on terminal menu)
      Scroll to bottom of terminal on keypress option
      Utilise RISC OS Select socket pollwords (unrequire Sockwatch)
      Moved to StubsG for everything. One sane build environment
      Ensure correct use of SocketWatch module
      Ensure correct use of ZapRedraw module. Ensure at least 0.39 used
      Don't gobble DA address space for ZapRedraw area
      Improved icons
      Better selection handling
      Keep to hires font in EY0 modes
      Works correctly with Internet 4.xx and 5.xx
      Updated French resources
      Reduced memory usage
    Bugs fixed:
      Shift-PageUp/Down are properly handled locally to move scrollbar
      Updates to French resources
      Correct pasting of line endings and chomping of multiples
      Handle inverted commas in ANSI task commands correctly
      Cope with insane scroll regions being requested
      Improved handling of linefeeds in scroll regions
      Terminal resizing bug solved
      Allow line editor size to be altered properly
      Other miscellaneous line editor fixes
      Correctly handle dragging of files to line editor
      Keep cursor-type menu open when choosing with Adjust
      Correctly reset resize window on Adjust-Cancel
      Correctly reset hotlist editor window on Adjust-Cancel
      Cope with long URLs
      Correctly implemented reverse tabulation command
0.2032r : December 7th 2002
    New features:
      French messages
      Ctrl-F2 closes disconnected sessions
      Added "linux" terminal type
      Improved method for detecting URLs
      Menu ticks added
      Selection-pasting only adds newlines at line end
      Small change to selected-area highlight colouring
      Caret drawn in window when it first opens
    Bugs fixed:
      Corrected pasting of large amounts of text to ANSI tasks
      Various optimisations and speedups
      Data load ack now sent
      Country lookup fixed
      Terminal scrolling on NEL
      Fixed memory leak on URI loading
      Fix pasting of large files
      Don't report errors twice
0.2020r : February 20th 2002
    New features:
      Iconised window naming
      Cope with and translate control characters when pasting
      Warn about open sessions on quit/shutdown
      Paste URL/URI files rather than launching them
      New choices section for 'miscellaneous' options (eg blinking)
      Versioned choices files
      Mouse support for Shift/Ctrl/Alt combinations
      Dynamic resizing of window -- optionally only when CTRL is held
      Accept user:pass@host format as a host entry for auto logon
      Handling of "telnet:user:pass@host:port" URL format
      Two types of terminal cursor : block or underline.
      Character underline support
      Display terminal size in scrollbar when dynamically resizing
      Multitasking speed when pasting large amounts
      Optional line editor can now default to 'off'
      Don't unnecessarily add blank spaces to end of lines
      Allow pasting of HTML, ask user when pasting other types
      RISC OS 3.5+ style error categories
      Positioning of new terminal windows is more standardised
      Better cursor drawing and display of 'ghost' cursor
      Large memory savings -- smarter use of ZapRedraw
      Terminal reset
      Handle 'stop bold' command and use it in ANSI saving output
    Bugs fixed:
      7bit/8bit VT escape sequences corrected
      Selection of rows when dragging selection a long way out of window
      Resizing on a mode change correctly
      Position cursor correctly when terminal resizes
      Hold on to selected area correctly when terminal resizes
      Fixed crashing on font change
      Ensure ZapRedraw at least 0.39 as we don't like earlier versions
      Double-clicking on IPs now does what you'd expect it to
      Swap top T bottom T around
      Corrected shutdown sequence so that desktop can be shutdown cleanly
      Some reasonably large internal cleanup and restructuring
      Read size of toolsprites from WIMP -- correctly position line editor
      Save as ANSI inserts proper ANSI sequences!

0.2010r : September 16th 2001
    New features:
      Remote mouse support (pico -m, mc, links etc work nicely now)
      Support basic telnet://hostname/ URL launching (no user/password yet)
      Inverse video emulation
      Session spooling (logging)
      Support X11 DISPLAY passing to remote
      Implemented save/resore cursors
      Support for blinking characters
      Accept telnet requests to suppress go ahead
      Global clipboard support
      File loading (dragging of files to session window)

      80/132 column switching doesn't change width on terminal reset now
      Better support ANT broadcast launching of URLs
      Improved recognition of URLs under double-click in terminal window
      Builds with new unixlib file structure
      Runs templheadr from a specified location
      Change menu wording ("Connect..." is now "New Session...")
      Much faster terminal drawing
      Hotlist editor gains "Copy" button - buttons grey-out at appropriate times
      Hotlist redraw cleaned up and made less flickery
      Hotlist items can now be dragged around to change the ordering
      Improve region scrolling behaviour

    Bugs fixed:
      Correctly turn off local echo (telnet to ArcadeBBS now works properly)
      Corrected hotlist editor tab ordering
      Hotlist editor couldn't create command for ANSItask
      Terminal speed reporting (and change reported speed to 38400)
      Selection saving fixes
      LINES/COLUMNS variables now correct (for use by ANSItask apps)
      Rare stack corruption solved
      Could sometimes continually swap cursor between two windows
      DNS lookup corrected

0.2000r : September 1st, 2001
      Recoded in C
      Supports vt100, vt102, vt220, xterm emulations
      Telnet and ANSI task connections
      URL launching

0.1306b : 1999 - 2001
    Initial BASIC versions

© Nettle developers, April 4th 2004.

SourceForge Logo