History Lesson: What Is a .sxi File? OpenOffice / StarOffice Impress

What is a .sxi file?

A .sxi file is a presentation from OpenOffice.org Impress (and matching StarOffice Impress) during the OpenOffice.org XML era. The Internet media type is application/vnd.sun.xml.impress. UK National Archives PRONOM records fmt/130 for OpenOffice Impress 1.0 (also StarOffice Impress 6.0): a ZIP+XML package with external signature .sxi. OpenOffice.org’s XML FAQ lists .sxi as the Impress default for that generation. The historical Impress template sibling is .sti (application/vnd.sun.xml.impress.template) — same family on disk, a template shell rather than a finished deck. The same OpenOffice.org XML suite family also includes .sxw (Writer), .sxc (Calc), and .sxd (Draw) — this article is about Impress .sxi only.

The format sits between two better-known neighbors. Earlier StarOffice ~3–5 Impress used binary .sdd (StarImpress). Later OpenOffice.org 2.0 / StarOffice 8 moved to OpenDocument Presentation (.odp) — an OASIS (Organization for the Advancement of Structured Information Standards) standard, later ISO/IEC 26300. Spell OpenDocument as that later open-standard family: it is based on OpenOffice.org XML but is not the same package and is not directly compatible by renaming.

Origin in plain language: after Sun Microsystems acquired Star Division, Sun and the OpenOffice.org community pushed an XML-based office package around 2000–2002. StarOffice 6.0 (about May 2002, based on OpenOffice.org 1.0) made OpenOffice.org XML the default Impress path — .sxi on disk instead of the old binary StarImpress package. Free OpenOffice.org 1.x and StarOffice 6/7 installs spread that mid-generation format across school, home, NGO, and corporate machines — which is why .sxi decks still turn up on CDs, USB sticks, and “OpenOffice” folders labeled in the early–mid 2000s.

Is .sxi the same as .odp or .sdd?

No — and that three-way mix-up is why these legacy files keep landing in “what is this?” searches. .sdd is the older binary StarImpress / StarOffice Impress package from the StarOffice ~3–5 era (OpenOffice.org MIME notes list application/vnd.stardivision.impress for StarImpress 5.x with the .sdd extension; Just Solve / Archiveteam’s StarOffice binary notes point at UK National Archives PRONOM records such as fmt/814, fmt/815, and x-fmt/360 for StarOffice Impress binaries). Spell OLE2 only when you mean that older compound binary family — many StarOffice binary packages used Object Linking and Embedding version 2 structured storage, not a ZIP of XML.

.sxi is OpenOffice.org XML: a ZIP of XML parts, default for StarOffice 6 & 7 and OpenOffice.org 1.x (~2002). .odp is OpenDocument Presentation, which arrived with OpenOffice.org 2.0 / StarOffice 8 around May 2005 as the open-standard successor. So the generation shift is: .sdd (binary StarImpress) → .sxi (OpenOffice.org XML package) → .odp (OpenDocument). Same product family over time; three different on-disk packages. A text editor and a rename will not turn a .sxi into a valid .odp. Changing .sxi to .sdd or .odp in Explorer does not convert anything.

Why won’t PowerPoint open .sxi?

Modern Microsoft PowerPoint does not natively open .sxi. Double-clicking a .sxi in 2026 fails as an unsupported format — not because the deck is blank. You need a conversion path to a modern presentation such as PPTX or OpenDocument Presentation (.odp). Do not expect every animation, master-slide quirk, or embedded media path to survive unchanged.

Descendants of the OpenOffice.org line — notably LibreOffice — still import legacy OpenOffice.org XML, which is why a .sxi that PowerPoint refuses may still open in a free office suite. That import path is not the same as PowerPoint “supporting” the format natively. Renaming .sxi to .ppt or .pptx does not convert anything either.

How the bytes work (ZIP+XML / OpenOffice.org XML)

On disk, a .sxi is a ZIP archive of XML and package parts — spell ZIP as the familiar compressed-folder container, and MIME as Multipurpose Internet Mail Extensions (the Internet media-type label). Inside you typically find an uncompressed mimetype file declaring application/vnd.sun.xml.impress, plus content.xml, styles.xml, meta.xml, settings.xml, and META-INF/manifest.xml, with optional embedded images and other parts. PRONOM’s internal signature for fmt/130 looks for that ZIP header plus the Impress MIME declaration and a meta.xml with office:version="1.0". That package shape is why a hex dump can look “almost like” a later .odp — and why renaming still fails.

Contrast with the previous generation: many StarImpress .sdd files are binary / compound packages, not a ZIP of XML. Contrast with the next generation: .odp is OpenDocument’s ZIP+XML successor, standardized through OASIS and later ISO/IEC 26300. Same family story; different package contracts.

OpenOffice.org XML, OpenDocument, and why .sxi files still sit on disks

Free OpenOffice.org 1.x in the early–mid 2000s, school and home installs, NGO archives, and StarOffice 6/7 corporate deployments all saved Impress decks as .sxi. Ownership of the line later moved from Sun to Oracle (Sun acquisition closed January 2010; the product briefly became Oracle Open Office and was discontinued in 2011), while community forks carried the codebase forward as Apache OpenOffice and LibreOffice. Some migrations stopped at OpenOffice.org XML and never finished the later jump to .odp. CD and USB backups labeled “OpenOffice” still turn up in 2026 with class decks, pitch slides, and side projects that outlived the machines that created them.

A PowerPoint window that refuses .sxi is not proof the presentation is empty. A ZIP listing that shows content.xml is not proof you can paste the slides into a modern deck without a real conversion. These are legacy files from the middle generation of a product line that moved through binary StarImpress, OpenOffice.org XML, and OpenDocument.

Legacy File Converter lists StarOffice / OpenOffice Impress / .sxi among supported presentations on Supported File Types and converts them locally on Windows. Nothing is uploaded — see also Convert Legacy Files Without CloudConvert. For the matching Calc story in the same OpenOffice.org XML suite, see History Lesson: OpenOffice Calc (.sxc); for the earlier binary Writer story in the StarOffice line, see History Lesson: StarWriter (.sdw); for PowerPoint’s own lineage, see History Lesson: PowerPoint (.ppt).