ShowSlate

Mac-first live event compositor and show control for layered scenes, Preview/Program switching, recording and multiple local displays.

Product page · Download · Conference workflow · User guide

Warning

Mac-first public beta / work in progress. The packaged Apple Silicon Mac app has been exercised through real operator and recording workflows. Windows packages build in native CI, but have not yet been manually validated on physical Windows hardware. ShowSlate is not production-certified: evaluate it off-air and test the exact computer, displays, media, capture devices, audio route and fallback before a live event. ShowSlate can be one component in a staffed production system. It is not intended to replace specialist crew roles, redundant signal paths or independent backup hardware.

ShowSlate is a local show-control workspace for small live productions. Build a visual Program from reusable layered scenes, prepare it privately in Preview, use TAKE to send it live, then record or route Program to one or more local displays. A scene can combine pictures, video, PDF pages, colors, text, a timer, application windows, displays, cameras and UVC capture devices. Every destination can use its own Canvas, resolution and scaling mode, with optional multi-surface projector mapping.

The included Conference Desk workflow adds a rundown, LIVE/NEXT/GO, speaker timing, cue-driven lower thirds, show-folder import and role-based room displays. It is intended for conferences, corporate events, education, community venues, houses of worship and small AV teams that need more structure than a media player but less complexity than a broadcast switcher.

Is ShowSlate the right tool?

Choose ShowSlate when a small event team needs to prepare scenes, run a conference-style cue list and coordinate several local room screens without an account or subscription. It is especially suited to small conferences, corporate meetings, education, community venues and rehearsed event playback.

Tool	Best fit	Where ShowSlate differs
ShowSlate	Local event visuals, cues, timers, lower thirds and several room displays	A free workflow joins rundown, layered scenes, Preview/Program, recording and output routing.
OBS Studio	Streaming, encoding, recording, filters and plugin-based broadcast workflows	Keep OBS for streaming; ShowSlate is organized around room screens and event cues.
Resolume Arena	High-performance VJ playback, effects and advanced projection mapping	Arena is the mature specialist; ShowSlate is simpler, free and conference-oriented.
ProPresenter	Polished presentation, worship, lyrics and stage-display workflows	ProPresenter has a deeper presentation ecosystem; ShowSlate is a general layered local compositor.

ShowSlate is not a replacement for every one of these products. Its useful niche is the space between a simple media player or timer and a full broadcast, VJ or presentation suite.

Need only a large countdown, OBS overlay, phone remote and simple rundown? Use the smaller ProTimer. Choose ShowSlate when you need layered scenes, Preview/Program switching, live inputs or several controlled outputs.

Live compositor workflow

1. Open Composer, choose the Canvas resolution and create a scene.
2. Add and arrange media, color, text, timing or a local live input as ordered layers.
3. Prepare the scene in Preview, verify it, then use TAKE or Cut to send it to Program.
4. Open Outputs, assign each destination to an explicit display, choose fullscreen/window placement and set its independent output Canvas, resolution and scaling.
5. For projectors or LED processors, open Map projector, create one or more surfaces, choose source pixels in Input Selection, then align them in Output Mapping before applying the route.
6. Enable Program audio on at most one local output when a video or capture source needs sound.
7. Select Record Program in the top bar when the final Program should be captured locally. Recording settings are under Settings > Recording.

The room workflow

1. Put rundown.csv or schedule.tsv and the event media in one folder.
2. Select Import Show Folder, review media matches and assign the Audience display.
3. Add any Confidence, Timer, Stream Graphics or Door Agenda destinations.
4. Run Preflight and Test outputs. A route is not marked live until its renderer confirms the current revision.
5. Enter Live Mode. Trigger prepared scenes or clips from the performance deck, or select the next rundown cue and press GO CUE.

Selecting a row prepares NEXT and never changes LIVE. GO creates one transaction and sends one consistent Program revision. The built-in Load conference demo action lets you try the workflow without preparing files first.

Live Mode performance deck

Live Mode is a second, performance-focused way to operate the same ShowSlate show. It does not create a separate project or bypass Preview/Program safety: it turns every scene in the selected composition into a column and its ordered sources into clip cells, while continuing to use the same Program renderer, output routes and rundown.

• Preview First prepares a scene without changing Program; TAKE SCENE sends it with the selected Cut or Fade transition.
• Direct is an explicit temporary trigger mode for rehearsed VJ-style operation. Leaving Live Mode restores the normal Composer safety setting.
• Trigger or hide one clip without replacing the rest of the current Program scene.
• Pin a logo, event bug, camera frame or other layer so it survives scene changes.
• Use the selected clip dock for Preview, Program or Both transport control when the source is playable media.
• Keep conference cues available in the compact rundown strip with BACK and GO CUE.
• Switch compositions without rebuilding the show; only scenes assigned to the active composition appear in its deck.

Show editing and imports are locked while Live Mode is active. Return to Composer to create scenes, arrange layers, change sources or edit the rundown.

Output roles

Role	Intended destination	What it shows
Audience	projector, LED wall or room display	Linked media, holding screens, timer and full Program content
Confidence	presenter confidence monitor	Current cue, next cue, speaker details, timer and urgent messages
Timer	dedicated stage timer display	A clean large timer and urgent messages only
Stream Graphics	transparent window for OBS or vMix testing	Lower thirds and show graphics without the room background
Door Agenda	display outside the room	Room name, current session, next session and clock

Each role can be fullscreen, windowed, an exact pixel size or a grid region. ShowSlate does not silently move a route to another monitor when a display disappears.

Multi-output and projector mapping

• Send the same live Program to multiple displays at the same time.
• Give every destination its own standard or custom Canvas resolution, frame rate and Fit / Cover / Fill scaling.
• Assign a fullscreen, windowed, exact-size or grid destination without changing the source scene.
• Build several independently named surfaces on one output and duplicate surfaces when preparing adjacent projectors or LED regions.
• Use Input Selection to crop the exact source pixels from a standard or custom composition Canvas.
• Use Output Mapping to position and rotate each surface, then choose four-corner perspective correction or a linear mesh up to 4 x 4 cells.
• Drag perspective, mesh and polygon-mask points directly on the output canvas. Use Grid, Checker or Crosshair calibration patterns with optional surface labels.
• Set per-surface visibility, Solo, opacity, edge overlap, blend gamma and black level while aligning multiple projectors.
• Apply mapping to the complete Program, not only to one media layer. Scene media, timer, text, logos and lower thirds stay together.
• Keep unavailable displays fail-closed: a missing projector is reported instead of silently moving the output elsewhere.

The mapper is still beta software. It provides perspective and bounded linear-mesh correction, polygon masks and manual edge blending, but it does not provide spline/Bezier warping, automatic camera calibration, projector color matching or certification for a particular venue chain. Calibrate and rehearse on the exact projectors, processors and surfaces before a live show.

Composer and live sources

Open Composer to build the visual Program as an ordered stack of layers. A scene can combine:

• pictures, local video, PDF pages and solid colors;
• text and the live ShowSlate timer;
• an application window or an entire display;
• a camera or UVC capture card, with an optional audio input.

Set a standard, square, vertical, UHD or custom Canvas resolution and frame rate. Drag and resize sources in Preview, edit exact position, size, opacity, rotation and fit in the inspector, then use TAKE to send the prepared scene to Program. Preview remains private until TAKE unless Direct Program is explicitly enabled.

Live capture is local to the ShowSlate desktop app and its desktop output windows. Browser/OBS URLs do not carry local window, display or capture-card streams. Program audio is off by default and can be enabled on only one local output to prevent echo and feedback.

Record Program

Select Record Program in the main header to capture the exact Program canvas without the operator interface. The button shows elapsed time while recording and stops the same recording when selected again.

Open Settings > Recording to choose:

• save folder and filename prefix;
• Program, 1080p, 1440p, 4K or custom output dimensions;
• 24, 25, 30, 50 or 60 fps;
• automatic format selection, MP4/H.264 or WebM;
• quality preset or a custom video bitrate;
• whether enabled Program audio is included, plus its audio bitrate.

ShowSlate prefers MP4/H.264 when the installed Electron/operating-system encoder supports it and falls back to WebM in Automatic mode. Recordings are written incrementally rather than held as one complete file in memory. Keep enough free disk space, record to a fast local drive and rehearse the exact resolution, frame rate, media and audio route before an event.

Full-quality and large media

ShowSlate does not resize, recompress or transcode imported pictures and videos. Media up to 512 MB is normally cloned or copied into the app library; larger files are linked to their original disk location and streamed in byte ranges, so multi-gigabyte video does not need to be loaded into RAM or duplicated on the internal drive. Keep linked files and their external drive connected at the same path for the entire show.

Playback has no fixed ShowSlate file-size cap. The practical limit is the show computer, codec and media: prefer a fast local SSD, hardware-decodable MP4/H.264 or HEVC where supported, and rehearse the exact resolution, frame rate and output count. Very large still images must still be decoded into GPU/RAM memory. Portable .showslate-show and .showslate-lt packages intentionally remain limited to 200 MB per embedded asset; disk-linked media is not silently embedded.

Install ShowSlate

Most users need one file only. On an Apple Silicon Mac, download the DMG below. GitHub's automatic Source code ZIP and TAR.GZ files are developer archives and will not install the app.

Status	Your computer	Download	Install
Primary tested beta	Apple Silicon Mac (M1 or newer)	Download ShowSlate DMG	Open the DMG and drag ShowSlate to Applications.
Experimental, unverified on physical hardware	Windows 10/11 x64	Download Windows Setup	Run Setup and follow the installer; use it off-air and report hardware results.

The portable Windows EXE is an advanced no-install option and carries the same unverified Windows status. The previous 0.12.0-beta.2 release remains available for comparison and rollback.

First-launch security warning

The public beta is not yet Apple-notarized or Windows Authenticode-signed.

• On macOS, confirm the app came from this repository, then use System Settings > Privacy & Security > Open Anyway if required.
• On Windows, SmartScreen may show Unknown publisher. Continue only for the installer downloaded from this repository.
• Optional integrity hashes are in SHA256SUMS.txt.

See the system requirements, known limitations and exact beta verification. Intel Mac is not currently published.

Show folder format

The importer scans the selected folder safely, manages smaller assets in ShowSlate storage, links large originals in place and conservatively matches each cue by the media filename or an exact cue title.

session,duration,speaker,speaker title,company,media,room
Opening,05:00,Ana Markovic,Conference Host,Example Events,opening.png,Main Room
Keynote,30:00,Dr Maya Chen,Keynote Speaker,Northstar,keynote.pdf,Main Room
Coffee Break,15:00,,,,break.png,Main Room

Supported folder media includes PNG, JPEG, WebP, GIF, AVIF, BMP, SVG, MP4, WebM, OGV, MOV, M4V and PDF. For Excel workbooks, export the rundown sheet as CSV/TSV or paste the rows into the wizard. Import behavior and the full column reference are in Conference Desk workflow.

Included production tools

• Rundown with NEXT, LIVE, GO, planned times, actual timing and post-show CSV reports.
• Countdown, stopwatch and clock with warning colors, overtime, chimes and speaker messages.
• Screen content for images, video, PDF pages, text, logos, timer and blank states.
• Custom-resolution Composer with reusable scenes, ordered layers, Preview/Program switching and drag/resize editing.
• Window/display capture and camera/UVC capture-card layers with optional local Program audio.
• Local Program recording with selectable resolution, frame rate, format, quality, save location and enabled Program audio.
• Lower Third Studio with cue-driven dynamic fields, shapes, logos, images and muted video.
• Explicit multi-display routing with per-destination Canvas settings, render acknowledgements and unavailable-display blocking.
• Multi-surface projector mapping with separate input/output transforms, perspective or linear-mesh warp, polygon masks, calibration patterns and manual edge-blend controls.
• Autosave, crash recovery and portable .showslate-show and .showslate-lt packages.
• Local phone remote, backstage view, Signal Light, HTTP and OSC control.
• English default UI, full Serbian UI and 35 core language packs with English fallback.

Deliberate scope

ShowSlate can arrange and locally record live and media sources for room displays, but it is not a streaming encoder, multibus audio mixer, NDI router, PTZ controller or multi-room cloud platform. Keep OBS, vMix or dedicated production hardware where live streaming, broadcast-grade multitrack recording, advanced audio or complex switching is required. The product remains focused on dependable visual composition, show control and straightforward Program capture for small event teams and a small set of local destinations. In larger or show-critical productions, use it as one component of a staffed, redundant signal chain rather than the only control point.

External OBS/vMix alpha behavior is not certified in this beta. Test the exact show computer, displays, network, media and capture path off-air before every event. Show-critical productions still need an independent fallback timer and rundown.

Documentation

• Conference Desk workflow and CSV reference
• User Guide
• System Requirements
• Known Limitations
• Languages
• Companion / HTTP / OSC
• Testing
• Signing and release
• Public beta verification
• 0.12.0 beta 3 release notes
• Architecture
• Privacy

Build from source

Requires Node.js 22.12 or later.

git clone https://github.com/srdjankotarlic/showslate.git
cd showslate
npm ci
npm start

Run deterministic checks with npm test. Display and packaged renderer checks require an available graphical display; see Testing.

Privacy and network safety

The core workflow is local-first and does not require an account. Show files and imported media remain on the show computer unless the operator exports or shares them. Browser, remote, backstage and Signal Light pages are served on the trusted production LAN. Do not expose local ports directly to the public internet; see Security and Privacy.

Feedback

This is a public evaluation beta, not a production-certified release. Try the built-in demo off-air, then use GitHub Discussions for workflow feedback or open a bug report with the app version, operating system, display setup and reproducible steps.

License

MIT - free to use, modify and distribute. Keep the copyright and license notice with substantial copies.