Supporting IE6 – a poison chalice or the holy grail?

One of the big benefits of Caplin’s browser-based SDP platform, Caplin Trader, is that it can run in virtually any browser without the need for plugins or special configuration.

This is no mean feat for a complex, high performance, low latency trading portal framework written in JavaScript and running to >250KLOC. Although IE8, Firefox, Safari and Chrome are similar enough to make it relatively straightforward to support each of them, IE7 and, particularly, IE6 are a different story. They are riddled with quirks and bugs in their layout, rendering and memory management engines. In addition, developer tool support is starting to lag. Worst of all, their performance is diabolical compared with the recent crop of competitors.

However, IE6 is often one of our customers’ main target browsers by default. Sadly the big financial institutions, and to a lesser degree their clients, run with locked-down and often out-of-date desktop components. This limits their capacity to upgrade or install new browsers, though it’s true that some of the smaller firms are able to do so more easily.

So, should we continue to support IE6? How should we encourage our customers and users to move to newer browsers? What are the benefits of doing so?

Why support IE6?

A large amount of engineering effort has to go into making Caplin Trader components behave and perform well in IE6. To say our developers would rather see it burn in hell is an understatement. A number of them use RobotJohnny’s amusing cartoon for their desktop background, and I even recently discovered on of our teams had sneaked a joke story card onto their board entitled “Drop Support for IE6” signed by all the developers!

On the other hand our customers need us to support IE6, at least for the time being. There may be some light at the end of the tunnel as I have heard that a couple of large international investment banks are planning to mass roll-out IE8 by the end of the year.

So in answer to the first question, yes, we will continue to support IE6 for the foreseeable future. Given this, what are the considerations we need to make to do this and how can we encourage users to upgrade?

IE6 performance

Here’s a graph, compiled last September by John Resig, of comparative JavaScript performance across different browsers. You can clearly see that IE7 (he didn’t even bother with IE6!) is an order of magnitude worse than most of the current browsers.

One clear benefit of our continued support for IE6 is that it forces us to produce components and libraries that perform well in that browser. All of our automated functional and performance tests are run across a range of browsers, but IE6 is considered the baseline – if it doesn’t work or perform in IE6 it’s not good enough!

This means that in the newer browsers Caplin Trader literally flies. Using it in FF3.5 or Chrome is really something – faster and more responsive than a lot of desktop apps I use every day!

Getting the most out of Caplin Trader

It’s one thing for our developers to enjoy Caplin Trader at its best, but really we want the end users to have this enhanced experience too! We’ve been experimenting with the best way to encourage them to move onto a newer browser if they can. One approach is to detect their browser and give them an information message that encourages them to upgrade if they can.

This seems like a good, and obvious idea – tell the users to upgrade their browser! However, all is not necessarily what it seems. Mark Trammel, over at Digg, recently did some very interesting user research to try and understand why on earth there was still a steady 10% of users visiting their site using IE6. (Note – this is a retail site, our experience of financial institutions suggests that their IE6 user base is at least 40%, perhaps higher!)

The interesting result (as shown below) is that 3 out of 4 users would upgrade browser if they could:

This means that constantly popping up a warning that tells users to upgrade is at best annoying, and at worst may infuriate them so much they stop using the application! For this reason our dialog tries to give both an encouraging friendly message (rather than a command or a warning) and also a way to prevent future popups (a checkbox). Hopefully this provides a good balance and will encourage users that can to upgrade, and those that can’t to put pressure on their IT departments to do so for them…

Poison chalice or holy grail?

In summary, there is a clear cost in engineering effort (not to mention developers’ hairlines!) to continuing supporting IE6. But this is currently outweighed by the benefits of ubiquitous reach and the fact that targeting a browser that’s an order of magnitude slower than most of the others means we consistently produce high performing code, without allowing performance complacency to set in.