Here are the data structures with brief descriptions:

CMAUG_FMT_SPEC
CMDATA_STRPOOL	A pool of immutable text strings. Deduplicates strings to save memory
CMDATA_TABLE
CMDATA_VECTOR	A vector of uniformly-sized objects, stored contiguously
CMFILE_CADDY
CMFILE_HANDLE
CMFMT_STRUCT	Generic image description struct
CMFMT_STRUCT_BMPFILE
CMFMT_STRUCT_BMPINFO	BITMAPINFO struct that comes before Windows bitmap data
CMHTML_PARSER
CMHTML_TAG
CMHTML_TAG_BASE
CMLISP_AST_NODE
CMLISP_ENV_NODE
CMLISP_EXEC_STATE	Current execution state to associate with a MLISP_PARSER
CMLISP_PARSER
CMLISP_STACK_NODE
CMLISP_VAL
CRETROCON
CRETROFLAT_3DTEX
CRETROFLAT_ARGS	Struct containing configuration values for a RetroFlat program
CRETROFLAT_BITMAP	Platform-specific bitmap structure. retroflat_bitmap_ok() can be used on a pointer to it to determine if a valid bitmap is loaded
CRETROFLAT_CACHE_ASSET
CRETROFLAT_INPUT	Struct passed to retroflat_poll_input() to hold return data
CRETROFLAT_STATE	Global singleton containing state for the current platform
CRETROFLAT_VIEWPORT	The viewport data struct
CRETROFONT
CRETROGLU_SPRITE
CRETROGLU_SPRITE_PARMS	If draw lists are disabled, this struct holds a list of params for retroglu_set_sprite_clip() so that the sprite can be drawn without a list
CRETROGLU_TILE
CRETROGUI
CRETROGUI_CTL
CRETROGUI_CTL_BASE	Fields common to ALL RETROGUI_CTL types
CRETROGXC_FONT_PARMS
CRETROHTR_RENDER_NODE
CRETROHTR_RENDER_TREE
CRETROTILE	A struct representing a tilemap
CRETROTILE_COORDS	This is not currently used for anything, but is provided as a a convenience for game logic
CRETROTILE_DATA_BORDER
CRETROTILE_DATA_DS	Internal data structure used by retrotile_gen_diamond_square_iter()
CRETROTILE_LAYER
CRETROTILE_PARSER
CRETROTILE_TILE_DEF