Dictionaries & translators
- Vortaro
Esperanto definitions of Esperanto words, with examples. Based on the definitive PIV: Plena Ilustrita Vortaro. Requires (free) registration. - La Simpla Vortaro
Esperanto definitions of Esperanto words. - Reta Vortaro
Words in thematic groups, inc. Belarto (fine arts). - Dicts.info
Translations between Esperanto and English. - NZEA: Australian & New Zealand to Esperanto
- Google Translate
Imperfect, but a good place to start.
Grammar & word usage
- Plena Manlibro de Esperanta Gramatiko
Exhaustive discussion, with examples, of Esperanto grammar. In Esperanto. - Lingvohelpilo
Get instant feedback on any Esperanto text you want to enter, from a grammatical point of view. - Tekstaro de Esperanto
Search for any Esperanto word or phrase in up to 69 exemplary Esperanto texts to see how it has been used.
In defence of Esperanto
All pages in English:
- Some Comments on Ignorance About Esperanto by Claude Piron
- Esperanto: Frequently Asked Questions
Inc. ‘What are some common objections to Esperanto? How do speakers of Esperanto respond to them?’ - Esperanto and the ideology of constructed languages, by Donald Broadribb
Miscellaneous
- Google in Esperanto
- Vikipedio
The Esperanto version of the world’s largest online encyclopedia. - Duolingo
Learn Esperanto on a smartphone, tablet or computer (free) - Lernu!
Free, interactive courses with exercises, sounds, and illustrations, plus more - AEA: Australian Esperanto Association
Every page in English and Esperanto.
I felt that there had to be more sites in Esperanto that weren’t just about Esperanto and it was driving me nuts that I couldn’t find them. I’ll have to check out eo-Wikipedia articles more and try and find the other sites.