Lectern
Show one window on the projector instead of your whole screen.
Download for Windows Privacy policy Terms of use
A small toolbar on the shared window lets you zoom, highlight and add notes while you present, without leaving your editor. Notifications and other windows never reach the projector, and your laptop screen stays yours.
Tech stack
- Electron
- Node.js
- HTML, CSS and JavaScript
- koffi (Windows APIs)
- desktopCapturer
- electron-builder
- electron-updater
What it does
- Pick one window to show, with search and minimised windows included, or deliberately share a whole screen
- Choose the projector on a map of your screens, with Identify screens
- A floating toolbar only you can see, plus shortcuts for zoom, highlight and follow the mouse
- Zoom by clicking, dragging a box or scrolling, with a view that stays put or follows your mouse
- Highlight a box or a whole line, a spotlight that dims everything else, movable notes, and a cursor ring with click ripples. Marks clear themselves when you scroll.
- Privacy: freeze the picture, freeze automatically while you're in another app, show a Back in a moment card with your own message, and stop by itself if the projector is unplugged or the laptop sleeps
- A live preview of what the room sees, a clock and a zoom slider
- A picture guide, a What's new card after updates, and Feedback that opens a GitHub issue
- Works with any projector, by cable or wirelessly, and in online lectures by sharing Lectern's own window in Teams or Zoom
How it works
- Five windows work together: the control panel, the full-screen projector stage, a see-through overlay, the floating toolbar and the guide.
- Windows functions are called through koffi to track where windows are, what's in front, and focus, minimise and restore. There's nothing to compile and no admin rights needed.
- Windows are captured with Electron's screen capture, so one can be shown even when other windows cover it.
- Comes as an installer, a portable exe or a zip. The installed version updates itself, and the others check GitHub and offer the new download.
- A capped local diagnostic log that never records note text or other apps' window titles.
Planned next
- Slides mode: Lectern's own presenter view for PowerPoint. The slide show goes to the projector, while the laptop shows the slide to draw on, the next slide, your notes and a timer.