Twelve demos, one per package

Every slide of the deck drawn live in the page, with a thumbnail strip and zoom.

Try: Click a thumbnail, zoom in, and select some text - it stays real text at every size.

Click a shape and drag it, colour its fill or its text, type in it or delete it; undo; download the file.

Try: Click the title, drag it somewhere else, pick a text colour from the toolbar, then double-click it and type.

Why a shape looks the way it does: which of the slide, its layout, the master or the theme decided each property.

Try: Pick a shape and read down the chain; a property marked inherited is one the slide never wrote.

A .pptx is a ZIP of XML parts that point at each other; this lists them and draws the links.

Try: Pick a part to see its first bytes, its content type and what it links to.

The XML of one part, edited in place and written back without touching a byte you did not change.

Try: Pick a slide part, change one attribute, and read the exact bytes that differ - then undo it.

What is inside the deck - slides, shapes, charts, fonts, media - counted off the main thread.

Try: Open a bigger deck and watch the counts arrive while the page stays responsive.

The 33 checks that keep PowerPoint from asking to repair a file, run on this deck.

Try: Open a rule to read its evidence, then drop a deck of your own and see what it finds.

The deck saved back out: only edited parts are rewritten, everything else streams through as it came in.

Try: Press Export, read which parts were rewritten and which streamed through untouched, and download it.

The 187 preset shapes PowerPoint knows, and the handles that reshape them.

Try: Pick a preset and drag a handle; the value a save would write updates as you drag.

How colours, gradients, patterns, dashes and arrowheads are computed, each measured against PowerPoint.

Try: Move a gradient stop or a colour transform and watch the output follow.

How text is measured, wrapped and shrunk to fit, the way PowerPoint does it.

Try: Type into the box and watch the line breaks move and the autofit step change.

Slides rendered in Node when this site was built, with no LibreOffice and no browser.

Try: Copy the command shown and run it on a deck of your own.