The Nahdlatul Ulama was founded in 1926 by Muhammad Hasyim Asy'ari in East Java.  In opposition to the Muhammadiyah, the NU wanted to promote the idea of Indonesian Islam, a nationalistic take on the religion which combines with native customs and rituals.  This form of Islam is much more open to mysticism.  In addition to the Qur'an and Hadith, the NU also embraces the use of fiqh and adat, or customs, for answers to questions.  NU scholars also collaborate to find answers to questions, a practice called ijma'.  However, "because each ulama is autonomous, a decision made in a higher council is not binding for lower-level councils or for individual ulama." 
Pesantren are Islamic boarding schools. The NU's pesantren are lead by a kiai, or a male master of Islam.  The kiai do not receive payment for their work with Qur'an but have a variety of things they can do to earn money, like venture into politics.  Kiai, like Sufi masters, encourage study of tasawwuf, or mysticism.  Also like Sufi masters, students of the pesantren visit the grave of the kiai. On the anniversary of the kiai's death, "the pesantren organizes elaborate festivities" in rememberance (khaul).  Initially, the NU was not overtly supportive of women's education.  Women were not really a part of the NU until 1957, when they were finally able to join the legislature.  Despite this, there was a pesantren open to women as early as 1919.  However, leader Kiai Bisri was not all that fond of the women's rights movement. He believed that being in the pesantren would give women something to do and "felt that it would teach them discipline."  It wasn't until 1934 that women's education was officially sanctioned.  Women can teach in the pesantren, but "are only allowed to teach female students so as 'not to bring men into temptation.'"  Less is expected of female students in the pesantren as well:
Many pesantren require a less rigorous curriculum for female students than for male students. Women study the same texts but, for example, read smaller numbers of pages then male students; thus they end up with less knowledge of the Islamic sources and teachings.