glXFreeContextEXT frees the client-side part of a GLXContext that was created with glXImportContext. glXFreeContextEXT does not free the server-side context information or the XID associated with the server-side context.glXFreeContextEXT is part of the EXT_import_context extension, not part of the core GLX command set. If GLX_EXT_import_context is included in the string returned by glXQueryExtensionsString, when called with argument GLX_EXTENSIONS, extension EXT_vertex_array is supported.