Learn Patch by building software.

Start here

You can learn Patch entirely in the browser. Open Patch Studio, edit the source, press Run, and watch the result. The visual Designer edits the same Patch source instead of maintaining a hidden form file.

create text message = "Hello, Patch!"
show message

Command-line quick start

patch check app.patch
patch run app.patch
patch build app.patch --target web
patch doctor --json

check validates source, run executes supported programs, build creates a selected artifact, and doctor reports compiler/backend health. Machine-readable JSON contracts are available for supported commands.

Tutorials

These tutorials use syntax that is exercised by the repository test suite and current examples. For the full step-by-step handbook, open the dedicated Tutorials page; for a browsable program library, use Examples.

create number count = 0

window "Counter" size 420, 240:
  text "Count: {count}" at 24, 24 size 220, 32
  button "Add" as add_button at 24, 72 size 120, 38

when add_button clicked:
  change count:
    add 1

create number score = 0

repeat 4:
  if count == 2 or count == 4:
    change score:
      add count

show score

create thing player:
  name = "Mia"
  score = 0

allow reward:
  player.score may increase up to 10

make reward(player):
  change player:
    add 5 to score

do reward(player)
show player.score

create list fruits = ["Banana", "Mango"]

window "Fruit Picker":
  listbox "Apple", "Banana", "Cherry", "Mango" as fruits

when fruits changed:
  change fruits:
    set = value

Language guide

Quick syntax reference

For exact grammar and edge cases, use the language specification. The user guide intentionally teaches the stable current surface instead of reproducing every parser rule.

GUI applications and Patch Studio

Patch Studio is a source-backed RAD environment. The editor, Designer, Object Inspector, Project Tree, Resource Manager and component tools operate on the same project source. There is no separate hidden persistent form model.

Forms and multi-window applications

Named Forms can be opened and closed through Patch application behavior. The Designer materializes only the active Form's controls while preserving source-backed shells for the other Forms. Runtime events now reconcile keyed Forms so unchanged Form DOM can remain stable.

Designer performance model

The primary Designer preview uses a declaration-only design snapshot instead of executing application behavior. Large projects use active-Form materialization. Current runtime rendering uses stable keyed Form/control identities, preserves bounded transient browser state around changed-Form replacement, and updates Tabs locally rather than rebuilding every Form.

Run, build and distribute

Patch exposes different output paths rather than pretending every backend has identical capabilities.

Signing status matters: Windows Offline Studio is currently unsigned by Authenticode, Linux is unsigned, and macOS uses ad-hoc signing only. Production Developer ID/notarization and Windows signing remain explicit open release work.

Example programs

Use these as starting points instead of writing everything from an empty editor. The repository contains a larger compatibility and research corpus; these are the most useful entry points for application developers.

Technical reference

One current map of Patch. The current product line is Patch beta.36, Change IR 0.10, Studio project bundle v4 and Native GUI IR 1.9 / payload v19 / runtime v1.10. Current RAD/native product work does not widen the beta.32 formal runtime-correspondence claim.

Language and compiler

Assurance and research

Native and release contracts

Patch keeps the Current Ready Native GUI IR 1.9 / payload v19 / runtime v1.10 contract alongside explicit older compatibility contracts. Payload v17/runtime v1.8 remains an Offline Compiler compatibility path, while IR 1.2 / payload v12 / runtime v1.3 remains the frozen TreeView line. Newer features never silently reinterpret older contracts.

Project and roadmap