This is going to be a short post. It may look like stating the obvious, but I was again reminded the other day that there are still frameworks and tools that do not have their default encoding set to UTF-8. So, two requests:
To framework authors and contributors: use UTF-8 by default, everywhere.
To developers: if you see a non-UTF-8 default, report a bug / request improvement.
I mostly look at the web side of the story, but same goes for desktop software.
The site UTF8Everywhere is also an advocate for this, you can take a look at the manifesto.
If using only English, why not stick to ISO-8859-1? If you only use latin script, you don’t lose anything from UTF-8 – it’s a variable length encoding and the initial symbols (corresponding to the ASCII ones) take the same amount of space.
Why you should use UTF-8? Because otherwise you will get tons of nasty encoding-related problems.
To conclude: Use UTF-8 by default