What's promised, and what isn't

Office engines are usually described in general words: “an Office replacement”, “full compatibility”. Such words can neither be verified nor fixed in a contract. Below is what stands behind each of them in the case of SumOffice: on the left the familiar wording, on the right what is actually promised and verifiable on your files.

General phrasing	What’s actually promised
A replacement for Word and Excel.	An embeddable office processor for your product: editing DOCX and XLSX files, saving with a reopen check, automation, and an interface under your brand.
Full compatibility with Microsoft Office.	Matching behavior on an agreed set of your documents, for the listed capabilities, and within the bounds of the declared matrix.
We support XLSX and DOCX.	For every format and every operation, it’s recorded separately: whether it’s read, edited, saved, and whether unsupported markup is preserved. This is already public: 13 spreadsheet formats and what you can do with each file type in documents.
We have VBA.	Its own runtime for an agreed subset: inspect the project, see the plan and the changed cells before running, run with a limit, apply or roll back. What is not supported—COM, external libraries, certain statements—is rejected with a message rather than faked; the contents of the subset are fixed in the matrix.
We have Power Query.	Queries are read, saved without loss, and refreshed by its own M language engine: sources, steps, preview, load, refresh. An unsupported source gets an explicit refusal with a migration path rather than a silent failure; the list of supported sources is fixed in the matrix.
We’re the fastest.	Instead of a slogan, measurements on your own documents: typical and worst-case time, memory, the amount of data loaded, saving and reopening.
White-label delivery.	You own the shell, the brand, sign-in, storage, and processes; SumOffice is responsible for the meaning of the document and the spreadsheet.
An agent edits the document.	An agent works through the same operations contract and history as a human: inspect, plan, preview the result, get confirmation, apply or roll back.

The platform in brief

Note

SumOffice is an embeddable office platform for anyone who needs their own editor, on par with Word and Excel, inside their product. You keep your brand, users, storage, security, and workflows. We deliver SumDoc for DOCX, SumSheet for XLSX, the Rust core, a ready-made editor surface, a developer kit — already working for documents, still taking shape for spreadsheets — automation, and a capability matrix. It all starts with a limited pilot on your real documents and ends with an enterprise profile that includes acceptance, availability commitments, and a version-support period.

Questions before you start

• Which operating systems, which technology is your application built on, and which embedding method do you need at the first stage?
• Which three to five of your real documents will decide whether the product fits?
• Which ten user actions need to work without Microsoft Office?
• Which of these are critical: comments, tracked changes, tables, fields, headers and footers, formulas, charts, pivot tables, Power Query, VBA?
• Where are documents stored: on the computer, inside your perimeter, in the browser, in a document-management or accounting system, in the cloud?
• What are the security requirements: where the data physically resides, leak control, logging, the delivery inventory, signatures, audit?
• Do you need agents, and which operations are they allowed to read, propose, and apply?

Next

• Verify what’s promised on your own files — Pilot and acceptance.
• What’s locked in by the contract — Commercial packaging.
• What isn’t covered yet — Risks and honest boundaries.
• Start small — early access request.