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TailWimp Lite

What is it and what is it not?

TailWimp Lite is a simple utility for rearranging Risc OS Wimp windows using keyboard short cuts, inspired by tiling window managers 0 such as i3 1 and Sway 2. It supports moving and reshaping windows to cover halves of the screen (horizontally or vertically), as well as the four corner quadrants, minus optional paddings to allow for access to the icon bar, iconised windows etc.

As signified by the Lite in the name, TailWimp Lite is not a fully fledged tiling window manager, nor an approximation of one. It doesn't keep any state of what windows are managed and acts only on the current (topmost) window.


The available movements are:

  • ModKey+Arrow Key – moves the current window in the direction specified, anchoring it to the margin in the direction of movement.
  • ModKey+Space – moves the current window to the centre of the screen, without manipulating its size, not respecting padding.
  • ModKey+Return maximizes the current window, while respecting padding.

The current window is defined as the topmost window over all, and ModKey defined as is either Logo or Alt. The default is Logo, but note that Logo key presses are not forwarded properly to Risc OS under RPCEmu 3, since they are captured by the host OS. Therefore Alt works better in this setting, but using this may not be ideal, since Risc OS uses Alt for a lot of things. The ModKey is configurable, see Choices below.

The moved window will be maximized (or centred, if it cannot cover the whole extent) in the perpendicular dirction to the movement, unless it is already anchored to one of those margins. This means that two moves, one vertical and one horizontal in any order, will get the window into a corner quadrant. The exception is if a window in a corner is moved in one of the directions where it is already anchored. It will then be maximized/centred in the perpendicular direction, i.e a window in the bottom left corner moved left will be maximized vertically. This gives a total of 8 positions reachable with the arrow keys, and an additional two configurations using the centre and maximize movements.

If padding is specified, space on the desktop will be reserved around the windows to allow access to the icon bar, iconized windows and the like. By default, only bottom padding is non-zero, in order to show the icon bar. See Choices below for information on how to configure padding.


Choices can be set by selecting Choices... from the icon bar menu. This allows you to set paddings for left, right, top and bottom margins in OS screen units (usually 2 per 1 px). By default only bottom padding is non-zero, in order to show the icon bar. You can also select whether you want Logo or Alt as ModKey. The default is Logo – see Usage above for some considerations on which to choose.


Help, release notes and license are available in the icon bar menu.


You can find the latest released version under Releases on the GitHub project 3, where you can also find the source, in case you want to modify it or build it your self. Be advised that the source may contain untested features! The GitHub project page can be opened by clicking the Bumbarrel icon in the Program information window, available from the icon bar menu under Info.

System requirements and compatibility

This software has been tested on Risc OS Open 5.X 4 on Raspberry Pi and in the RPCEmu emulator 3. It might work on earlier versions of Risc OS as well. If you try it, please let me know! Also, please see Usage above for some notes on using Tail Wimp Lite under RPCEmu.

Getting more help, making suggestions and reporting problems

The preferred way of communicating a suggestion or a problem is to submit an issue in the GitHub project 5. If you have questions, you can also try asking in the Risc OS Open forum 6 if you think the question is of general interest, or you can contact me directly on for example !ChatCube 7, Telegram 8, or matrix 9, or by emailing me I use the handle skymandr for all of these.

Why TailWimp?

It's a polyglottal pun. Bumbarrels are best birds.

Why Lite

Shortened from light due to space restrictions. This refers to the fact that this is not a full tiling window manager, just a tool for moving windows about. If some day I can get this to work in a satisfactory manner, I may give making a more comprehensive window management tool a go, in which case that will be called just TailWimp.

License and disclaimer

TailWimp Lite - utility for rearranging Wimp windows using keyboard

Copyright (C) 2021 Andreas Skyman (Bumbarrel Computing)

Many features in this program are highly derivative of Steve Fryatt's examples from which have been relicensed from European Union Public License v1.2 for the purpose of this program.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see