Here are two VERY handy utilities I use for when I have to type classical Greek (polytonic Greek, with the complicated accents and breathing marks) and when I have to type in Polish (a funky extended Latin character set with various diacritics).
For Greek, I use Randy Hoyt's fantastic took at TypeGreek.com, which allows you to type Beta code and get Unicode-compliant Greek which you can cut-and-paste into any application. You can use this for typing Greek characters with or without accent marks. Here's a screenshot:
For Polish, I use Tomasz Szynalski's TypeIt.org, which offers support for several languages, including Polish, which is at Polish.TypeIt.org. The other languages it supports are Czech, French, German, Italian, Portuguese, Romanian, Spanish, Swedish and Turkish. Here's a screenshot:
What great online utilities, both completely free and very easy to use! I've never been very good at understanding how to install alternate keyboards, etc., but these web-based options allow me to do my typing without any special effort at all!
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