• Supersize that background, please!

    Learn how create full-screen backgrounds that resize to fit the viewport using CSS3 backgrounds and CSS3 media queries.

  • Practical HTML 5

    My current train of thoughts on how you can best author HTML 5 websites today by using a phased approach for your transition.

  • Using timeline labels to dispatch events with the ActionScript 3.0 TimelineWatcher class

    Use the ActionScript TimelineWatcher class to programmatically monitor the timeline while keeping it separate from your application logic.

  • Providing alternative content for SWF files

    Improve the overall user experience and searchability of your flash content by using alternative content and following a couple of simple guidelines.

  • Detecting Flash Player versions and embedding SWF files with SWFObject 2

    Use the latest Flash embed and Flash Player detection method that is easy to use, supports web standards, enables alternative content, and offers a comprehensive API for JavaScript developers.

  • Flash Embedding Cage Match

    Ever had to embed Flash into a web page and just been plain confounded about the best way to do it? Be confused no more! In this article I cut through the arguments and opinions about the many techniques available.

  • Modern JavaScript, tien vuistregels wijzen je de weg

    The Dutch translation of "Ten good practices for writing JavaScript in 2005" for one of Dutch finest online magazines.

  • Unobtrusive dynamic select boxes

    Learn how to create accessible dynamic select boxes using unobtrusive JavaScript and progressive enhancement.

  • Ten good practices for writing JavaScript in 2005

    Learn how to create modern JavaScript code using the latest techniques, like unobtrusive scripting, handy tools and common sense.

  • Unobtrusive show/hide behavior reloaded

    Learn how to solve a common display problem for all current unobtrusive show/hide techniques and the introduction of a new concept: Cloning hidden content.

  • Exploring Footers

    With old-school table layout methods, vertical positioning is a piece of cake. With CSS layout, it's a piece of something else. In this article I show how to regain control of footers and other vertically positioned layout elements via CSS, JavaScript, and the DOM.

  • Behind the scenes of Garden Party

    The process and thoughts behind my CSS Zen Garden submission.

Open source

  • Woordflitsen

    Woordflitsen (flash cards) is an educational tool to help 6 to 8 year old kids with the speed of reading (or doing maths). Also available as a downloadable ZIP file. In 2014 Woordflitsen 1.2 was released to include a configurable pause in between the display of the words (Woordflitsen 1.2 ZIP file). Woordflitsen is promoted by SchoolbordPortaal.

  • SWFObject 2

    SWFObject 2 is an open source project by Geoff Stearns, Michael Williams and myself with the goal to unify and improve all existing Flash Player embed methods. It is the successor of SWFObject 1.5, the Adobe Flash Player Detection Kit and UFO. Also available on GitHub.

  • Flash Player embed test suite

    The Flash Player embed test suite assesses the browser support for various markup-based plug-in embed methods. It includes information on parameters about support for different Flash content publish settings, streaming, and scriptability.

  • Unobtrusive Flash Objects (UFO)

    UFO is an unobtrusive DOM script that detects and embeds Flash objects and contains several other great features.


  • HTML5 and friends

    Presentation I gave at Blast Radius' Biertje o'clock about the advent of a powerful open web platform. This presentation is also available in PDF format.

  • SWFObject 2 masterclass

    My presentation for the <head> 2008 online conference. Learn how to use SWFObject 2 to embed Adobe Flash content into web pages. This session will discuss all ins and outs, from the most basic hello world example to topics like Full Browser Flash, ActionScript-to-JavaScript communication, alternative content for people without Flash, SEO, Adobe Express Install and hacking around with the new SWFObject 2 JavaScript API. This presentation is also available in PDF format.

  • SWFObject 2: The fine art of embedding Adobe Flash Player content

    My presentation for FITC Amsterdam. It shortly discusses the history and goals of the SWFObject 2.0 project, thoroughly explains the underlying problems it aims to solve, and gives an overview of the final solution. This presentation is also available in PDF format.

  • Flash binnen het Gilde van Front-Enders

    Fronteers is an association that aims to further professionalize the front-end programming discipline within the Netherlands. On it's founding congres I had the pleasure to give a presentation titled Flash within the Dutch Guild of Front-end Programmers. In this presentation I explained why Flash should be a discipline within the brand new association and how this can be fulfilled properly in an initiative that was originally founded by people from the web standards community. You can find a translated English version here.

Other work

  • My TheFWA interview

    Rob Ford interviewed me for TheFWA.

  • The JavaScript Anthology

    I was the technical editor of The JavaScript Anthology, which is one of the most complete question-and-answer books on JavaScript. It's a collection of over 100 thoroughly-tested, customizable and elegant solutions that will show you how to add usable and accessible interactivity to your site: from slick drop-down menus, to style sheet switchers, to AJAX applications, and much more.

  • Garden Party

    My contribution to CSS Zen Garden. Zen Garden is an online showcase that demonstrates what can be accomplished visually through CSS-based design.


Bobby van der Sluis works as a Principal Design Technologist at frog in Amsterdam, where he helps companies envision and create new consumer and professional products.

Bobby van der Sluis He is passionate about designing and developing great user interfaces and is specialised in open web standards - like HTML5, CSS3 and JavaScript. He likes to work in multi-disciplinary teams of specialists at the intersection where technology meets design and business.

Bobby has over 17 years of professional experience in product development, online advertising and IT environments, and has created over 100 websites, web applications and online campaigns for many renowned clients like Nike, Nintendo, HP, Disney, TomTom and the Dutch Government. His work has won a series of industry awards, including Cannes Lions, Eurobest Awards and WebAwards.

Besides his professional track record, Bobby also used to be an active member of the online web community and an author of popular open source software. He has spoken at several conferences and has written a series of articles for online magazines like A List Apart and Adobe Devnet. He is the technical editor for a book named the JavaScript Anthology.

Several years ago Bobby decided to take a sabbatical from his community activities and to focus on his increasing professional and family responsibilities. As a result, currently this website only contains an archive of past work.