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Ream

Scope & limitations

The conversion core is broad and spec-driven, but ECMA-376 is vast and Ream does not implement all of it — this page is an honest map of what works and what doesn’t yet.

Implemented

Section titled “Implemented”

WordprocessingML (§17)

  • Text, runs and the full style cascade (docDefaults → styles → direct formatting).
  • Tables — auto / fixed layout, §17.4 border-conflict resolution, cell shading, vertical merge and grid span, nested tables.
  • Lists and numbering (abstractNum, level overrides), multi-level.
  • Sections — per-section page size and orientation, headers and footers.
  • Inline and floating images (PNG / JPEG / JPEG2000).
  • Tracked changes (w:ins / w:del).

SpreadsheetML (§18)

  • Grids, shared strings, number formats and dates (incl. the 1904 date system).
  • The print model — gridline suppression, print area, fit-to-page scaling, repeated print titles, manual page breaks, horizontal/vertical centering.

Graphics & math

  • DrawingML shapes (preset and custom geometry, gradients, group shapes, theme colors).
  • Charts — bar/column, line, pie/doughnut, area, scatter, stacked.
  • OfficeMath — fractions, scripts, radicals, n-ary operators, functions, limits, delimiters, matrices, accents; inline and display.

Typography

  • Type0 + CIDFontType2 embedding with subsetting.
  • Knuth–Plass line breaking, Liang hyphenation (en / ru).
  • OpenType ligatures and kerning (GSUB/GPOS), mark positioning.
  • BiDi (UAX #9), Arabic cursive joining.

PDF / compliance

  • PDF/A-1, -2, -3 at levels a / b / u — all formally veraPDF-validated.
  • Tagged PDF — logical structure tree, headings, tables, lists, figures with alt text, /Lang, pagination artifacts.
  • Digital signatures — PKCS#7 detached, ECDSA; object streams; JPEG2000 images.

Not yet

Section titled “Not yet”
  • Legacy .doc / .xls (the binary OLE/CFB formats) — Ream parses only the OOXML ZIP+XML formats. Re-save as .docx / .xlsx.
  • Font measurement parity with a specific renderer. Ream lays out correctly for the font you supply; pixel-exact agreement with another tool requires that tool’s exact font metrics.
  • Assorted deep-tail OOXML features are tracked as the project grows.

Validation

Section titled “Validation”

Development is corpus-driven: documents are converted, compared against a LibreOffice “golden” render (structural text diff + rasterized visual diff), and PDF/A output is gated through veraPDF. Untrusted corpus files run inside a locked-down Docker sandbox.