Encyclopaedia of islam online

The Brill encyclopaedia contains:

• The Encyclopaedia of Islam Second Edition (EI2, published from 1955-2005)
  A continuation of the first edition (1913-1936). The EI2's geographical scope encompasses the old Arabic-Islamic empire, the Islamic countries of Iran, the Ottoman Empire, Central Asia, the Indian sub-continent, Indonesia and many other Islamic countries. Entries are on religion, geography, ethnology, history, topography, culture and Muslims who have distinguished themselves in any particular aspect.
  
  
• The Encyclopaedia of Islam THREE (EI3, Third Edition, 2007- present day)
  The third edition is an entirely new work, with new articles reflecting the great diversity of current scholarship and developments in methodology. EI3 is a 'work in progress', appearing in regular installments every year. Many of its entries have been completely rewritten from previous editions. Alongside 1400 years of history, the new scope includes comprehensive coverage of Islam in the 20th and 21st Centuries, an even larger geographical scope (worldwide), a stronger focus on history, art, society, and culture, as well as Muslim minorities all over the world.