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Offline diagram tool

Visio-style diagrams, flowcharts and org charts without subscription lock-in.

Coming soon

Affordable premium, offline-first software. Local-first; no subscription trap. Culltron Max and Ultra X27 (Ultra X27 generation). Affiliate disclosure.

What this covers

Diagrams explain systems, processes and organisations. Diagram Max is an original SVG diagram editor that works offline.

The Culltron tools for this job

Diagram Max

An original SVG diagram editor (not a Visio clone).

  • Drag stencils onto the canvas and connect node ports with orthogonal connectors that route around other shapes.
  • Five stencil sets with 25 shapes (flowchart, network, org, process and infrastructure) and nine templates.
  • Automatic hierarchical layout, top-down or left-to-right.
  • SVG and PNG export from the same geometry engine as the editor.

Ultra X27: adds nested groups and swimlanes, node positions you can pin through auto-layout, connector priorities, shapes linked to CSV data with a review step, and up to 32 conditional style rules.

Limits: Diagram Max uses its own file format and does not claim to import or export Visio files.

Office Max

Documents, spreadsheets and slide decks in one offline-first desktop app.

  • A rich-text document editor with a structured citation registry, deterministic numbering and a bibliography you can refresh.
  • A spreadsheet formula engine running in the app, with 103 user-facing functions, A1 ranges and dependency recalculation that detects circular references.
  • A slide editor with a Present mode.
  • DOCX and XLSX import with a review step. Before a copy is made, the app shows what will be lost and what is supported. The original file is kept unchanged and is verified by checksum.
  • DOCX and XLSX export of the supported subset, plus local drafts and autosave.
  • A signed offline licence lease, so you can keep working without a connection.

Limits: Imports cover a supported subset; Word citation fields and syncing with external reference managers are not claimed. Import reports are local checksums, not a guarantee of full fidelity.

Who it is for

How it works

  1. Each Max app is a separate desktop product built on Culltron's shared, hardened platform.
  2. Files and records stay in a local folder on your machine, and the core tools work offline.
  3. A signed licence lease unlocks the paid edition. Ultra X27 adds advanced features that the server enforces.
  4. When you change a file, the app writes a new copy, often with a checksum receipt, instead of silently overwriting your original.

Frequently asked questions

Does it open Visio files?

No. Diagram Max uses its own format and exports SVG and PNG.

Does it lay diagrams out automatically?

Yes. Hierarchical layout runs top-down or left-to-right, and connectors route around other shapes.

What is in Ultra X27?

Swimlanes, nested groups, pinned positions, data-linked shapes and conditional styles.

Does it work without internet?

Yes.

Release status: built and tested in the repository. A public download appears only after signing, checksum verification and release approval; see Downloads.