- Gunung Bagging : a treasure trove for those keen on hiking volcanoes
- Tripcanvas Indonesia : a generalist lifestyle website that posts good to-do lists of places to visit especially in Java, Bali and Lombok
- Wikitravel : a collaborative Wiki about traveling. Really useful to find cheap accommodation and transport
- Lonely Planet forums : an old-school forum with some very knowledgable active members.
- Jakarta100bars : most comprehensive source about nightlife.
- Pelni : public inter-province ferry transportation, with prices and reliable schedules
- ASDP : public within-province ferry transportation, with prices and unreliable schedule
- The article about boat travel in Indonesia will probably be a useful complement
- Tiket.com : a private website acting a 3rd party re-seller for plane and train tickets. Efficient and good customer service. Traveloka is one of the reliable alternatives.
- Nias Heritage Museum : excellent website about Nias cultural sites
- Visit Nias Island : a great complement to the museum website.
- Wild Sumatra : a local eco-tourism agency based in Sungai Penuh, offering trips to Jambi and Bengkulu provinces. Run by passionated Luke Mackin. Tons of information and pictures, great both for those looking for a tour guide as well as independent traveler.
- Mentawai.org : plenty of information about traditional Mentawai culture
Bali and Nusa Tenggara
- Kalender Bali Digital : an online Balinese calendar giving you all the ritual special days and ceremonies (in Indonesian).
- Sumba Information : a great website about Sumba tourism and culture
- Geneviève Duggan’s website : lots of very interesting information about Savunese culture
- Flores Tourism : a great website by Flores tourism board.
- Bombastic Borneo : edited by a Malaysian Dayak. Tons of informations especially about Dayak festival all over Borneo.
Papua and Maluku
- East-Indonesia : a very comprehensive website about Maluku and Papua by Laszlo Wagner.
- Stay Raja Ampat : really comprehensive website about local accommodation in Raja Ampat
- Pusaka collection : an incredible online museum of traditional woven textiles of Indonesia
- Aural archipelago : a great project making field recordings of traditional music available online
- Timescape Indonesia Youtube channel : many short films shot in Indonesia before WWII.
- Kamus Besar Bahasa Indonesia : the most comprehensive online Indonesian dictionnary (no English translation)
- Bahasa Kita : tons of excellent articles by linguists
- Ruang Indonesia Bapak Bataone (in Indonesian) : good articles by, I presume, a Japanese expatriate
- Belajar Bahasa Indonesia : lots of points explained in a clear way