int  viewer_open(int viewer, const W3ADocumentInfo doc,
                         Widget  win, long id);
 int viewer_write(int viewer, long id, const char *buf, size_t nbytes);
  int  viewer_close(int viewer, long id);
  int  viewer_info(int viewer, long id, W3ADocumentInfo *doc);
 void viewer_event(int viewer, long id, long sourceid,
                         long eventtype, void *params);
 int agent_open(int agent, const char *url, int method, int flags,
                      const char *referer);
  int  agent_done(int agent, int fd);
 int agent_peek(int agent, int fd);
 int agent_read(int agent, int fd, char *buf, size_t nbytes);
 int agent_write(int agent, int fd, const char *buf, size_t nbytes);
  int  agent_close(int agent, int fd);
  int  agent_delete(int agent, const char *url);
  int  agent_info(int agent, int fd, W3ADocumentInfo *doc);
  int  filter_open(int filter, const char *from_type,
                        const char *from_params, const char *to_type,
                        const char *to_params, long id);
 int filter_write(int filter, long id, const char *buf, size_t nbytes);
 int filter_read(int filter, long id, char *buf, size_t nbytes);
  int  filter_close(int filter, long id);
  int  function_doit(int function, int code, int mid_x, int mid_y);
 void function_event(int function, long sourceid,
                           long eventtype, void *params);
  int  printer_open(int printer, const W3ADocumentInfo doc, long id);
 int printer_write(int printer, long id, const char *buf, size_t nbytes);
  int  printer_close(int printer, long id);
 int find_viewer(const char *mime_type);
 int find_agent(const char *protocol);
 int find_filter(const char *from, int n);
 int find_printer(const char *mime_type);
 void init_all_applets();
 void W3AbrowserInfo(W3ABrowserInfo *info);