It is well known that one can specify a [complex structure][1] on a real $C^\infty$ manifold in two equivalent ways: an atlas with holomorphic transition functions between charts and an [integrable almost complex structure][2]. One of the directions is straightforward. In the other direction, the celebrated [Newlander–Nirenberg theorem][3] states that an integrable almost complex structure induces a holomorphic atlas.

For [real analytic manifolds][4], I know only the atlas method (transition functions between charts are real analytic). My question: does there exist for real analytic manifolds an analog of an almost complex structure, an integrability condition and an analog of the Newlander–Nirenberg theorem?

At the moment, my suspicion is that the right analog should be an almost [CR structure][5] and a corresponding integrability condition (whatever those are). But unfortunately I've not really seen this written anywhere.


  [1]: http://en.wikipedia.org/wiki/Complex_manifold
  [2]: http://en.wikipedia.org/wiki/Almost_complex_manifold
  [3]: http://en.wikipedia.org/wiki/Newlander-Nirenberg_theorem#Integrable_almost_complex_structures
  [4]: http://www.encyclopediaofmath.org/index.php/Analytic_manifold
  [5]: http://en.wikipedia.org/wiki/CR_manifold