Editing SO (section)

==Science, technology, and mathematics==
===Biology and medicine===
*[[Syndromic obesity]], excess body fat occurring as part of a syndrome
*[[Sphincter of Oddi]], a muscular valve of the duodenum

===Computing===
* [[.so]], the top-level Internet domain of Somalia
* <code>.so</code>, a filename extension for a [[Shared library|shared object]] (a dynamic library or module) in Unix and Linux
* [[Shift Out]], an ASCII control character in computing
* [[Small-outline integrated circuit]]
* [[StackOverflow]], a programming Q&A site
* [[Sony]]'s mobile phones in Japan

===Mathematics===
* [[SO (complexity)]], second-order logic in descriptive complexity
* Special orthogonal group, a subset of an [[orthogonal group]]
** [[SO(2)]], a term used in mathematics, the group of rotations about a fixed point in the Euclidean plane
** [[SO(3)]], a term used in mathematics, the group of rotations about a fixed point in three-dimensional Euclidean space
** [[SO(4)]], a term used in mathematics, the group of rotations about a fixed point in four-dimensional Euclidean space
** [[SO(5)]], a term used in mathematics, the special orthogonal group of degree 5 over the field R of real numbers
** [[SO(8)]], a term used in mathematics, the special orthogonal group acting on eight-dimensional Euclidean space
** <math>\mathfrak{so}(n)</math>, the corresponding [[special orthogonal Lie algebra]]

===Physics and chemistry===
* [[Sulfur monoxide]]
* [[SO(10) (physics)]], a term used in particle physics, one of the grand unified theories is based on the SO(10) Lie group