To write an Elementary app, you can get started with the following:

 #include <Elementary.h>
 EAPI_MAIN int
 elm_main(int argc, char **argv)
 {
    // create window(s) here and do any application init
    elm_run(); // run main loop
    return 0; // exit 0 for exit code
 }
 ELM_MAIN()

To use autotools (which helps in many ways in the long run, like being able to immediately create releases of your software directly from your tree and ensure everything needed to build it is there) you will need a configure.ac, Makefile.am and autogen.sh file.

configure.ac:

 AC_INIT(myapp, 0.0.0, myname@mydomain.com)
 AC_PREREQ(2.52)
 AC_CONFIG_SRCDIR(configure.ac)
 AM_CONFIG_HEADER(config.h)
 AC_PROG_CC
 AM_INIT_AUTOMAKE(1.6 dist-bzip2)
 PKG_CHECK_MODULES([ELEMENTARY], elementary)
 AC_OUTPUT(Makefile)

Makefile.am:

 AUTOMAKE_OPTIONS = 1.4 foreign
 MAINTAINERCLEANFILES = Makefile.in aclocal.m4 config.h.in configure depcomp install-sh missing

 INCLUDES = -I$(top_srcdir)

 bin_PROGRAMS = myapp

 myapp_SOURCES = main.c
 myapp_LDADD = @ELEMENTARY_LIBS@
 myapp_CFLAGS = @ELEMENTARY_CFLAGS@

autogen.sh:

 *#!/bin/sh
 echo "Running aclocal..." ; aclocal $ACLOCAL_FLAGS || exit 1
 echo "Running autoheader..." ; autoheader || exit 1
 echo "Running autoconf..." ; autoconf || exit 1
 echo "Running automake..." ; automake --add-missing --copy --gnu || exit 1
 ./configure "$@"

To generate all the things needed to bootstrap just run:

 ./autogen.sh

This will generate Makefile.in's, the configure script and everything else. After this it works like all normal autotools projects:

 ./configure
 make
 sudo make install

Note sudo was assumed to get root permissions, as this would install in /usr/local which is system-owned. Use any way you like to gain root, or specify a different prefix with configure:

 ./configure --prefix=$HOME/mysoftware

Also remember that autotools buys you some useful commands like:

 make uninstall

This uninstalls the software after it was installed with "make install". It is very useful to clear up what you built if you wish to clean the system.

 make distcheck

This firstly checks if your build tree is "clean" and ready for distribution. It also builds a tarball (myapp-0.0.0.tar.gz) that is ready to upload and distribute to the world, that contains the generated Makefile.in's and configure script. The users do not need to run autogen.sh - just configure and on. They don't need autotools installed. This tarball also builds cleanly, has all the sources it needs to build included (that is sources for your application, not libraries it depends on like Elementary). It builds cleanly in a buildroot and does not contain any files that are temporarily generated like binaries and other build-generated files, so the tarball is clean, and no need to worry about cleaning up your tree before packaging.

 make clean

This cleans up all build files (binaries, objects etc.) from the tree.

 make distclean

This cleans out all files from the build and from configure's output too.

 make maintainer-clean

This deletes all the files autogen.sh will produce so the tree is clean to be put into a revision-control system (like CVS, SVN or GIT for example).

There is a more advanced way of making use of the quicklaunch infrastructure in Elementary (which will not be covered here due to its more advanced nature).

Now let's actually create an interactive "Hello World" gui that you can click the ok button to exit. It's more code because this now does something much more significant, but it's still very simple:

 #include <Elementary.h>

 static void
 on_done(void *data, Evas_Object *obj, void *event_info)
 {
    // quit the mainloop (elm_run function will return)
    elm_exit();
 }

 EAPI_MAIN int
 elm_main(int argc, char **argv)
 {
    Evas_Object *win, *box, *lab, *btn;

    // new window - do the usual and give it a name (hello) and title (Hello)
    win = elm_win_util_standard_add("hello", "Hello");
    // when the user clicks "close" on a window there is a request to delete
    evas_object_smart_callback_add(win, "delete,request", on_done, NULL);

    // add a box object - default is vertical. a box holds children in a row,
    // either horizontally or vertically. nothing more.
    box = elm_box_add(win);
    // make the box horizontal
    elm_box_horizontal_set(box, EINA_TRUE);
    // add object as a resize object for the window (controls window minimum
    // size as well as gets resized if window is resized)
    elm_win_resize_object_add(win, box);
    evas_object_show(box);

    // add a label widget, set the text and put it in the pad frame
    lab = elm_label_add(win);
    // set default text of the label
    elm_object_text_set(lab, "Hello out there world!");
    // pack the label at the end of the box
    elm_box_pack_end(box, lab);
    evas_object_show(lab);

    // add an ok button
    btn = elm_button_add(win);
    // set default text of button to "OK"
    elm_object_text_set(btn, "OK");
    // pack the button at the end of the box
    elm_box_pack_end(box, btn);
    evas_object_show(btn);
    // call on_done when button is clicked
    evas_object_smart_callback_add(btn, "clicked", on_done, NULL);

    // now we are done, show the window
    evas_object_show(win);

    // run the mainloop and process events and callbacks
    elm_run();
    return 0;
 }
 ELM_MAIN()