# \[ANN\] Slipshow! **URL:** \ **Category:** Community\ **Tags:** announce\ **Created:** [March 20, 2025, 8:55am UTC](https://discuss.ocaml.org/t/ann-slipshow/16337 "2025-03-20T08:55:06Z")\ **Posts on this page:** 1\ **Showing post:** 1
**Author:** ![panglesd](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/panglesd/32/3931_2.png) [@panglesd](https://discuss.ocaml.org/u/panglesd)\ **Post date:** [March 20, 2025, 8:55am UTC](https://discuss.ocaml.org/t/ann-slipshow/16337/1 "2025-03-20T08:55:06Z")
Dear reader, I am _absolutely thrilled_ to announce the release of slipshow `0.1.1` on this forum! As you have all noticed, that is a _huge_ leap from the previous version, `0.0.34`. (What can have motivated this?) Recall that [Slipshow](https://github.com/panglesd/slipshow) is a tool to prepare presentation support, that is based on scripted scrolling and zooming (instead of slides). I’ll use this single thread to announce all future versions of slipshow, to avoid polluting the global namespace, as it makes sense to keep this forum centered around OCaml, and this tool has nothing to do with OCaml … … well, almost nothing to do with OCaml, since in this version the engine has been fully rewritten in OCaml (hence the bold new version) and works much better! Making it a full OCaml project. Thanks, OCaml developers of open source libraries and language! To upgrade it, you can do: ```auto $ opam update $ opam upgrade slipshow ``` What? Some people don’t have it installed already? For those, it will be: ```auto $ opam update $ opam install slipshow ``` Now comes the moment you are all waiting for: the list of new features! > **TLDR** : > > - Engine rewritten in OCaml > - Fewer bugs when navigating back > - Stronger foundation (eg, for subslips) > - Custom scripts requires minor adjustments > - Breaking change in subslip HTML > > - Drawing now in SVG > - No more zoom issues > - Erasing works “per-stroke” > > - Revamped table of content > - Now based on title structure rather than subslips > > - New `--markdown-output` flag for converting to GFM > - Parser bugfixes > - License change: Now GPLv3 (previously MIT) > - npm distribution discontinued. > - Special thanks to NLNet for their [sponsorship](https://nlnet.nl/project/Slipshow/)! Dear readers, I am thrilled to announce the 0.1 release of Slipshow, the slip-based presentation tool! This is a _major_ minor release. While versions `0.0.1` to `0.0.33` have served well to experiment, this release marks a fresh start, aimed at being a solid foundation for a project with a clear direction. A huge thank you to NLNet for [sponsoring](https://nlnet.nl/project/Slipshow/) this milestone! So, what is new? Quite a lot, the main change being that the engine has been _fully rewritten_. ### The engine Started as a single file javascript project, the old engine evolved presentation by presentation – leading to numerous bugs, maintenance challenge or extensibility issue. (In other word, I did all I could not to touch it despite all the bugs) This release introduces a complete rewrite of the engine in OCaml, with new design choices that improve reliability and expandability. Let’s go over the key benefits and breaking changes. #### Navigating Forward… and Backward One of the greatest weakness of the old engine was handling backward navigation. Since it started as a simple “script scheduler”, going back wasn’t straightforward. The workaround involved taking a snapshot of… everything (the DOM, the state, …), to be able to go back in time. This had many bugs, in animations (such as the “focus” action), and in its iteraction with other features (such as drawing). So, what is new in this engine? The engine now records an undo function for each step of the presentation. While this may not sound much, it is a ton better in terms of development. It’s a much stronger foundation to build new features from. It’s also much more efficient for long presentations. In most cases, your old presentations will work without modification in the new engine. However, there is one case where it needs modification: when you include the execution of a custom script in your presentation. In this case, you need to return the function undo to undo the executed step: see the [documentation](https://slipshow.readthedocs.io/en/stable/syntax.html#custom-scripts)! (This is not ideal and better solutions are being experimented) #### Writing Previously, live annotations used the excellent [atrament](https://github.com/jakubfiala/atrament) library. While great in many cases, its bitmap-based approach caused blurriness when zooming. This release introduces a custom SVG-based annotation system, which eliminates zoom issues. Another change: erasing now works stroke-by-stroke instead of pixel-by-pixel. #### Table of content The old table of contents was based on the slip structure, which didn’t work well for presentations that primarily used a single slip (as is often the case with compiled presentations). The new sidebar-style table of contents is now generated from headers, making it more intuitive and aligned with the presentation’s structure—resulting in a much smoother navigation experience! #### Breaking change: Subslips The HTML structure for subslips has evolved, in particuler to avoid having to provide the scale of your subslips. Support for subslip in the new engine is not mature and will be announced in the next release, but bear in mind that if your presentation relies on them, you might want to wait a bit before migrating to the new engine! ### Compiler While this release focuses on the engine, the compiler has also seen improvements, including bug fixes (particularly in the parser) and a new feature: #### `--markdown-output` for markdown exports If you want to print your presentation or host it as a static webpage, the default format can be cluttered with annotations. The new `--markdown-output` flag lets you generate a clean, GitHub Flavored Markdown (GFM) file without annotations. ### Other A small but maybe important note: the license has changed, the project has transitioned from MIT to GPLv3, aligning better with its values. ### Conclusion Looking forward to your bug reports! --- _[View the full topic](https://discuss.ocaml.org/t/ann-slipshow/16337)._