Fish School Screensaver — A Living School With Its Own Society
This isn't a looping video of fish swimming past. Fish School Screensaver runs a real-time simulation built on the Boids flocking algorithm — a full school of up to 100 fish that thinks, reacts and lives together, frame by frame, exactly the way a real shoal does.
The school is the star. Watch a tight "bait ball" form, then dissolve into loose, curious exploration — all driven by each fish balancing five instincts every instant: keep its distance from neighbours, match the group's heading, stay close to the crowd's centre, avoid the tank walls, and dodge the plants and rocks around it. Tune the weight of each instinct and you literally reshape how the group swims — a loose, independent school, or a dense, marching-band formation.
They have real social lives. Every fish carries its own personality — timid or bold, curious or calm — plus its own hunger, stamina and fatigue. When a fish gets hungry, it peels away from the group to hunt; drop food with a single keypress and watch the school converge on the feast. Courtship unfolds in stages: a male locks onto a female, the pair swims side by side in perfect lockstep, then rejoin the crowd when the bond ends. Some fish chase, some wander, some cluster — and in Random mode, the school switches between all of these behaviours on its own, just like a natural shoal deciding its next move.
Endlessly alive, endlessly customisable. Choose from 25 species — angelfish, koi, blue tang, guppy, manta, shark and more — set the count, size and speed, pick a fixed species or let them change over time. Frame it all with 10 aquarium backgrounds and 23 transition animations, bubbles, ripples, and ambient water-flow sound. Rotate the whole tank in 3D with a drag; click the surface to send ripples through the water.
A single file. No setup fuss. One portable executable — no .NET or extra runtimes. It acts as a proper Windows screen saver, pauses quietly when you return, and captures a screenshot with one key. Try every feature free for 7 days; purchase once to keep the school swimming forever.
Requirements: Windows 10 1809 or later, an OpenGL-capable GPU, ~62 MB of disk.