new file mode 100644
--- /dev/null
+++ b/src/popupwin.c
@@ -0,0 +1,231 @@
+/* vi:set ts=8 sts=4 sw=4 noet:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read a list of people who contributed.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+
+/*
+ * Implementation of popup windows.  See ":help popup".
+ */
+
+#include "vim.h"
+
+#ifdef FEAT_TEXT_PROP
+
+/*
+ * Go through the options in "dict" and apply them to buffer "buf" displayed in
+ * popup window "wp".
+ */
+    static void
+apply_options(win_T *wp, buf_T *buf UNUSED, dict_T *dict)
+{
+    wp->w_maxwidth = dict_get_number(dict, (char_u *)"maxwidth");
+    wp->w_maxheight = dict_get_number(dict, (char_u *)"maxheight");
+    wp->w_winrow = dict_get_number(dict, (char_u *)"line");
+    wp->w_wincol = dict_get_number(dict, (char_u *)"col");
+    wp->w_zindex = dict_get_number(dict, (char_u *)"zindex");
+}
+
+/*
+ * popup_create({text}, {options})
+ */
+    void
+f_popup_create(typval_T *argvars, typval_T *rettv)
+{
+    win_T   *wp;
+    buf_T   *buf;
+    dict_T  *d;
+    int	    nr;
+
+    // Check arguments look OK.
+    if (!(argvars[0].v_type == VAR_STRING
+		&& argvars[0].vval.v_string != NULL
+		&& STRLEN(argvars[0].vval.v_string) > 0)
+	&& !(argvars[0].v_type == VAR_LIST
+	    && argvars[0].vval.v_list != NULL
+	    && argvars[0].vval.v_list->lv_len > 0))
+    {
+	emsg(_(e_listreq));
+	return;
+    }
+    if (argvars[1].v_type != VAR_DICT || argvars[1].vval.v_dict == NULL)
+    {
+	emsg(_(e_dictreq));
+	return;
+    }
+    d = argvars[1].vval.v_dict;
+
+    // Create the window and buffer.
+    wp = win_alloc_popup_win();
+    if (wp == NULL)
+	return;
+    rettv->vval.v_number = wp->w_id;
+    wp->w_p_wrap = TRUE;  // 'wrap' is default on
+
+    buf = buflist_new(NULL, NULL, (linenr_T)0, BLN_NEW|BLN_LISTED|BLN_DUMMY);
+    if (buf == NULL)
+	return;
+    ml_open(buf);
+    curbuf = buf;
+    set_string_option_direct((char_u *)"buftype", -1,
+				     (char_u *)"popup", OPT_FREE|OPT_LOCAL, 0);
+    set_string_option_direct((char_u *)"bufhidden", -1,
+				     (char_u *)"hide", OPT_FREE|OPT_LOCAL, 0);
+    curbuf = curwin->w_buffer;
+    buf->b_p_ul = -1;	    // no undo
+    buf->b_p_swf = FALSE;   // no swap file
+    buf->b_p_bl = FALSE;    // unlisted buffer
+
+    win_init_popup_win(wp, buf);
+
+    nr = (int)dict_get_number(d, (char_u *)"tab");
+    if (nr == 0)
+    {
+	// popup on current tab
+	wp->w_next = first_tab_popupwin;
+	first_tab_popupwin = wp;
+    }
+    else if (nr < 0)
+    {
+	// global popup
+	wp->w_next = first_popupwin;
+	first_popupwin = wp;
+    }
+    else
+	// TODO: find tab page "nr"
+	emsg("Not implemented yet");
+
+    // Add text to the buffer.
+    if (argvars[0].v_type == VAR_STRING)
+	// just a string
+	ml_append_buf(buf, 0, argvars[0].vval.v_string, (colnr_T)0, TRUE);
+    else if (argvars[0].vval.v_list->lv_first->li_tv.v_type == VAR_STRING)
+    {
+	listitem_T  *li;
+	linenr_T    lnum = 0;
+	char_u	    *p;
+
+	// list of strings
+	for (li = argvars[0].vval.v_list->lv_first; li != NULL;
+							      li = li->li_next)
+	    if (li->li_tv.v_type == VAR_STRING)
+	    {
+		p = li->li_tv.vval.v_string;
+		ml_append_buf(buf, lnum++,
+			       p == NULL ? (char_u *)"" : p, (colnr_T)0, TRUE);
+	    }
+    }
+    else
+	// TODO: handle a list of dictionaries
+	emsg("Not implemented yet");
+
+    // Delete the line of the empty buffer.
+    curbuf = buf;
+    ml_delete(buf->b_ml.ml_line_count, FALSE);
+    curbuf = curwin->w_buffer;
+
+    // Deal with options.
+    apply_options(wp, buf, argvars[1].vval.v_dict);
+
+    // set default values
+    if (wp->w_zindex == 0)
+	wp->w_zindex = 50;
+
+    // TODO: Compute the size and position properly.
+
+    // Default position is in middle of the screen, assuming a small popup
+    if (wp->w_winrow == 0)
+	wp->w_winrow = Rows > 5 ? Rows / 2 - 2 : 0;
+    else
+	--wp->w_winrow;  // option value is one-based
+    if (wp->w_wincol == 0)
+	wp->w_wincol = Columns > 20 ? Columns / 2 - 10 : 0;
+    else
+	--wp->w_wincol;  // option value is one-based
+
+
+    // TODO: set width based on longest text line and the 'wrap' option
+    wp->w_width = wp->w_maxwidth == 0 ? 20 : wp->w_maxwidth;
+    if (wp->w_maxwidth > 0 && wp->w_width > wp->w_maxwidth)
+	wp->w_width = wp->w_maxwidth;
+    if (wp->w_width > Columns - wp->w_wincol)
+	wp->w_width = Columns - wp->w_wincol;
+
+    // TODO: adjust height for wrapped lines
+    wp->w_height = buf->b_ml.ml_line_count;
+    if (wp->w_maxheight > 0 && wp->w_height > wp->w_maxheight)
+	wp->w_height = wp->w_maxheight;
+    if (wp->w_height > Rows - wp->w_winrow)
+	wp->w_height = Rows - wp->w_winrow;
+
+    wp->w_vsep_width = 0;
+
+    redraw_all_later(NOT_VALID);
+}
+
+/*
+ * popup_close({id})
+ */
+    void
+f_popup_close(typval_T *argvars, typval_T *rettv UNUSED)
+{
+    int		nr = (int)tv_get_number(argvars);
+
+    popup_close(nr);
+}
+
+    void
+popup_close(int nr)
+{
+    win_T	*wp;
+    win_T	*prev = NULL;
+
+    for (wp = first_popupwin; wp != NULL; prev = wp, wp = wp->w_next)
+	if (wp->w_id == nr)
+	{
+	    if (prev == NULL)
+		first_popupwin = wp->w_next;
+	    else
+		prev->w_next = wp->w_next;
+	    break;
+	}
+
+    if (wp == NULL)
+    {
+	prev = NULL;
+	for (wp = first_tab_popupwin; wp != NULL; prev = wp, wp = wp->w_next)
+	    if (wp->w_id == nr)
+	    {
+		if (prev == NULL)
+		    first_tab_popupwin = wp->w_next;
+		else
+		    prev->w_next = wp->w_next;
+		break;
+	    }
+    }
+    if (wp != NULL)
+    {
+	win_free_popup(wp);
+	redraw_all_later(NOT_VALID);
+    }
+}
+
+    void
+close_all_popups(void)
+{
+    while (first_popupwin != NULL)
+	popup_close(first_popupwin->w_id);
+    while (first_tab_popupwin != NULL)
+	popup_close(first_tab_popupwin->w_id);
+}
+
+    void
+ex_popupclear(exarg_T *eap UNUSED)
+{
+    close_all_popups();
+}
+
+#endif // FEAT_TEXT_PROP