Support for older javascript browsers

It happens that the error occurs in the old version of the popular browser, but it is so important, and there are so many visitors with this version that it would be good to fix it.

This is especially true of IE, which has the most significant differences between versions and, to a lesser extent, other browsers.

Next, we will talk about how to conveniently organize the installation of different versions of a single browser, for development and debugging.

Internet Explorer

Internet Explorer is tightly integrated with the system. Especially for IE <9.

This is all going on since ancient times, when Microsoft was accused of monopolism and tried to force a number of components, including the browser, to be removed from the operating system. But Microsoft didn’t want to do this, arguing that “the browser is too much integrated into the OS, is part of it and it’s impossible to remove it”. And, accordingly, I tried to integrate

Development and testing options for several versions of IE:

IE8 + emulation mode

In IE8 + there is an emulation mode, it switches to the toolbar, but it works incompletely.

By experience, it is 100% reliable in layout, but approximately 95% in JavaScript. Some errors are not reproduced.

IETester

One of the best emulation projects for old IE. Contains libraries from them, whenever possible tries to separate one IE from another, but it is not always possible.

It also works well with the layout, but in JavaScript, not all glitches and IE features are reproduced, and in addition, there are some additional errors.

Virtual machine, for example VirtualPC, VMware, VirtualBox, Parallels (Mac)

The necessary version of Windows with the corresponding IE is placed in the virtual machine.

This is the only completely reliable way.

There are also utilities that allow you to run the application without explicitly logging into the virtual machine, on the same taskbar with others. As if it is installed in the main OS. For example ThinApp, Sandboxie. You can use them, but inconveniences are possible if you have plug-ins installed on your browser, Visual Studio debugger (IE6,7), profiler (DynaTrace AJAX), etc.

You can use several approaches at the same time: emulation mode during development, and, if necessary, or for a 100% guarantee, launch a virtual machine with the correct version of IE.

Firefox

The Firefox browser is easier, but sometimes there are significant differences between its versions. Fortunately, Firefox can be delivered in multiple copies on one machine. There will be no problems.

Two versions of Firefox are usually supported: “current stable (or even beta)” and “minimum acceptable”. At the same time, auto-update is enabled in the first one, but not in the second one.

The only thing to be borne in mind is the “profile”, i.e. the directory in which the browser stores its settings and extensions. Physically, it is stored in the user's home directory. Under different Firefox they can be different, so you need to specify the profile explicitly.

Different versions of Firefox must have different profiles.

1. Profile must first be created. To do this, launch Firefox using the key:

   firefox.exe --profilemanager

   You can launch it from the installation directory or via the full path to Firefox, so that this is exactly the version you need.

   Firefox will display a list of profiles and allow you to create a new one.

2. In the future, a “shortcut” (or its equivalent, bash file, etc.) is created, which explicitly launches Firefox with the desired profile:

   C:\Program Files\FirefoxLatest\firefox.exe -P latest

3. To run multiple versions of Firefox at the same time, you need to add the option --no-remote .

Chrome, Opera

The old browser version is needed very rarely. It is so rare that it is easiest to remove the current version of the browser and install an older one, and then return the new one.

Also under Windows, you can use Chrome Portable and Opera Portable.