Modules
Here is a list of all modules:

GTC Extensions (Stable) | Functions and types that the GLSL specification doesn't define, but useful to have for a C++ program
GLM_GTC_bitfield | Allow to perform bit operations on integer values
GLM_GTC_color_space | Allow to perform bit operations on integer values
GLM_GTC_constants | Provide a list of constants and precomputed useful values
GLM_GTC_epsilon | Comparison functions for a user defined epsilon values
GLM_GTC_integer | Allow to perform bit operations on integer values
GLM_GTC_matrix_access | Defines functions to access rows or columns of a matrix easily
GLM_GTC_matrix_integer | Defines a number of matrices with integer types
GLM_GTC_matrix_inverse | Defines additional matrix inverting functions
GLM_GTC_matrix_transform | Defines functions that generate common transformation matrices
GLM_GTC_noise | Defines 2D, 3D and 4D procedural noise functions Based on the work of Stefan Gustavson and Ashima Arts on "webgl-noise": https://github.com/ashima/webgl-noise Following Stefan Gustavson's paper "Simplex noise demystified": http://www.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf <glm/gtc/noise.hpp> need to be included to use these functionalities
GLM_GTC_packing | This extension provides a set of function to convert vertors to packed formats
GLM_GTC_quaternion | Defines a templated quaternion type and several quaternion operations
GLM_GTC_random | Generate random number from various distribution methods
GLM_GTC_reciprocal | Define secant, cosecant and cotangent functions
GLM_GTC_round | Rounding value to specific boundings
GLM_GTC_type_precision | Defines specific C++-based precision types
GLM_GTC_type_ptr | Handles the interaction between pointers and vector, matrix types
GLM_GTC_ulp | Allow the measurement of the accuracy of a function against a reference implementation
GLM_GTC_vec1 | Add vec1, ivec1, uvec1 and bvec1 types
GTX Extensions (Experimental) | Functions and types that the GLSL specification doesn't define, but useful to have for a C++ program
GLM_GTX_associated_min_max | Min and max functions that return associated values not the compared onces
GLM_GTX_bit | Allow to perform bit operations on integer values
GLM_GTX_closest_point | Find the point on a straight line which is the closet of a point
GLM_GTX_color_space | Related to RGB to HSV conversions and operations
GLM_GTX_color_space_YCoCg | RGB to YCoCg conversions and operations
GLM_GTX_common | Provide functions to increase the compatibility with Cg and HLSL languages
GLM_GTX_compatibility | Provide functions to increase the compatibility with Cg and HLSL languages
GLM_GTX_component_wise | Operations between components of a type
GLM_GTX_dual_quaternion | Defines a templated dual-quaternion type and several dual-quaternion operations
GLM_GTX_euler_angles | Build matrices from Euler angles
GLM_GTX_extend | Extend a position from a source to a position at a defined length
GLM_GTX_extented_min_max | Min and max functions for 3 to 4 parameters
GLM_GTX_fast_exponential | Fast but less accurate implementations of exponential based functions
GLM_GTX_fast_square_root | Fast but less accurate implementations of square root based functions
GLM_GTX_fast_trigonometry | Fast but less accurate implementations of trigonometric functions
GLM_GTX_gradient_paint | Functions that return the color of procedural gradient for specific coordinates
GLM_GTX_handed_coordinate_space | To know if a set of three basis vectors defines a right or left-handed coordinate system
GLM_GTX_hash | Add std::hash support for glm types
GLM_GTX_integer | Add support for integer for core functions
GLM_GTX_intersect | Add intersection functions
GLM_GTX_io | Std::[w]ostream support for glm types
GLM_GTX_log_base | Logarithm for any base
GLM_GTX_matrix_cross_product | Build cross product matrices
GLM_GTX_matrix_decompose | Decomposes a model matrix to translations, rotation and scale components
GLM_GTX_matrix_interpolation | Allows to directly interpolate two exiciting matrices
GLM_GTX_matrix_major_storage | Build matrices with specific matrix order, row or column
GLM_GTX_matrix_operation | Build diagonal matrices from vectors
GLM_GTX_matrix_query | Query to evaluate matrix properties
GLM_GTX_matrix_transform_2d | Defines functions that generate common 2d transformation matrices
GLM_GTX_mixed_producte | Mixed product of 3 vectors
GLM_GTX_norm | Various ways to compute vector norms
GLM_GTX_normal | Compute the normal of a triangle
GLM_GTX_normalize_dot | Dot product of vectors that need to be normalize with a single square root
GLM_GTX_number_precision | Defined size types
GLM_GTX_optimum_pow | Integer exponentiation of power functions
GLM_GTX_orthonormalize | Orthonormalize matrices
GLM_GTX_perpendicular | Perpendicular of a vector from other one
GLM_GTX_polar_coordinates | Conversion from Euclidean space to polar space and revert
GLM_GTX_projection | Projection of a vector to other one
GLM_GTX_quaternion | Extented quaternion types and functions
GLM_GTX_range | Defines begin and end for vectors and matrices
GLM_GTX_raw_data | Projection of a vector to other one
GLM_GTX_rotate_normalized_axis | Quaternions and matrices rotations around normalized axis
GLM_GTX_rotate_vector | Function to directly rotate a vector
GLM_GTX_scalar_relational | Extend a position from a source to a position at a defined length
GLM_GTX_simd_mat4 | SIMD implementation of mat4 type
GLM_GTX_simd_quat | SIMD implementation of quat type
GLM_GTX_simd_vec4 | SIMD implementation of vec4 type
GLM_GTX_spline | Spline functions
GLM_GTX_std_based_type | Adds vector types based on STL value types
GLM_GTX_string_cast | Setup strings for GLM type values
GLM_GTX_transform | Add transformation matrices
GLM_GTX_transform2 | Add extra transformation matrices
GLM_GTX_type_aligned | Defines aligned types
GLM_GTX_vector_angle | Compute angle between vectors
GLM_GTX_vector_query | Query informations of vector types
GLM_GTX_wrap | Wrapping mode of texture coordinates
GLM Core | The core of GLM, which implements exactly and only the GLSL specification to the degree possible
Common functions | These all operate component-wise
Exponential functions | These all operate component-wise
Geometric functions | These operate on vectors as vectors, not component-wise
Integer functions | These all operate component-wise
Matrix functions | For each of the following built-in matrix functions, there is both a single-precision floating point version, where all arguments and return values are single precision, and a double-precision floating version, where all arguments and return values are double precision
Noise functions | Noise functions are stochastic functions that can be used to increase visual complexity
Floating-Point Pack and Unpack Functions | These functions do not operate component-wise, rather as described in each case
Angle and Trigonometry Functions | Function parameters specified as angle are assumed to be in units of radians
Vector Relational Functions | Relational and equality operators (<, <=, >, >=, ==, !=) are defined to operate on scalars and produce scalar Boolean results
Types | The standard types defined by the specification
Precision types | Non-GLSL types that are used to define precision-based types
Precision types | Non-GLSL types that are used to define precision-based types
Template types | The generic template types used as the basis for the core types