diff --git a/index.html b/index.html
index f4cd42d..37ab4aa 100644
--- a/index.html
+++ b/index.html
@@ -161,7 +161,11 @@ function run() {
 	req.onreadystatechange = function() {
 		switch (req.status) {
 			case 200:
-				output.innerHTML = req.responseText;
+				if (req.getResponseHeader("Content-Type") === "img/png") {
+					output.innerHTML = '<img src="data:image/png;base64,' + req.responseText + '"/>';
+				} else {
+					output.innerHTML = req.responseText;
+				}
 				break;
 			case 400:
 				output.innerHTML = '<pre class="error">'+req.responseText+'</pre>';
diff --git a/main.go b/main.go
index c3afed3..07e15b1 100644
--- a/main.go
+++ b/main.go
@@ -29,6 +29,8 @@ type Tool struct {
 	Name          string
 	Cmd           string
 	Args          []string
+	NeedsFile     bool
+	ContentType   string
 	Suffix        string
 	Description   string
 	Documentation map[string]string
@@ -36,31 +38,61 @@ type Tool struct {
 	BgColor       string
 }
 
-func (t Tool) execute(in io.Reader, w http.ResponseWriter) {
+func (t *Tool) execute(in io.Reader, w http.ResponseWriter) {
+	var args []string
+
+	if t.NeedsFile {
+		tmpf, e := ioutil.TempFile(".", "*"+t.Suffix)
+		if e != nil {
+			log.Printf("couldn't create tmp-file: %v\n", e)
+			http.Error(w, e.Error(), http.StatusInternalServerError)
+			return
+		} else if _, e = io.Copy(tmpf, in); e != nil {
+			log.Printf("couldn't write to tmp-file: %v\n", e)
+			http.Error(w, e.Error(), http.StatusInternalServerError)
+			return
+		}
+		defer os.Remove(tmpf.Name())
+		// log.Printf("using tempfile: %q\n", tmpf.Name())
+
+		args = []string{}
+		args = append(args, t.Args...)
+		args = append(args, tmpf.Name())
+	} else {
+		args = t.Args
+	}
+
 	var (
-		cmd      = exec.Command(t.Cmd, t.Args...)
+		cmd      = exec.Command(t.Cmd, args...)
 		err, buf = &bytes.Buffer{}, &bytes.Buffer{}
 	)
 
-	cmd.Stdin = in
+	if !t.NeedsFile {
+		cmd.Stdin = in
+	}
 	cmd.Stderr = err
 	cmd.Stdout = buf
 
 	if e := cmd.Run(); e == nil {
-		io.Copy(w, buf)
+		if t.ContentType != "" {
+			w.Header().Add("Content-Type", t.ContentType)
+			io.Copy(base64.NewEncoder(base64.StdEncoding, w), buf)
+		} else {
+			io.Copy(w, buf)
+		}
 	} else {
 		log.Printf("%s returned error\n", t.Name)
 		http.Error(w, err.String(), http.StatusBadRequest)
 	}
 }
 
-func (t Tool) compile() func(http.ResponseWriter, *http.Request) {
+func (t *Tool) compile() func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		t.execute(r.Body, w)
 	}
 }
 
-func (t Tool) svg() func(http.ResponseWriter, *http.Request) {
+func (t *Tool) svg() func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		name := filepath.Base(r.URL.Path)
 		if file, err := os.Open(filepath.Join(*savedir, name+t.Suffix)); err != nil {
@@ -75,7 +107,7 @@ func (t Tool) svg() func(http.ResponseWriter, *http.Request) {
 
 const maxSnippetSize = 64 * 1024
 
-func (t Tool) save() func(http.ResponseWriter, *http.Request) {
+func (t *Tool) save() func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		body, err := ioutil.ReadAll(io.LimitReader(r.Body, maxSnippetSize))
 		if err != nil {
@@ -112,7 +144,7 @@ func (t Tool) save() func(http.ResponseWriter, *http.Request) {
 	}
 }
 
-func (t Tool) load() func(http.ResponseWriter, *http.Request) {
+func (t *Tool) load() func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		name := filepath.Base(r.URL.Path)
 		if file, err := os.Open(filepath.Join(*savedir, name+t.Suffix)); err != nil {
@@ -125,7 +157,7 @@ func (t Tool) load() func(http.ResponseWriter, *http.Request) {
 	}
 }
 
-func (t Tool) index(tmpl *template.Template, data interface{}) func(http.ResponseWriter, *http.Request) {
+func (t *Tool) index(tmpl *template.Template, data interface{}) func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		err := tmpl.ExecuteTemplate(w, "index.html", map[string]interface{}{"Tools": data, "Cur": t})
 		if err != nil {
@@ -135,7 +167,7 @@ func (t Tool) index(tmpl *template.Template, data interface{}) func(http.Respons
 }
 
 func main() {
-	var tools = []Tool{}
+	var tools = []*Tool{}
 	var tmpl *template.Template
 
 	flag.Parse()
diff --git a/static/povray.js b/static/povray.js
new file mode 120000
index 0000000..e382383
--- /dev/null
+++ b/static/povray.js
@@ -0,0 +1 @@
+dot.js
\ No newline at end of file
diff --git a/tools.json b/tools.json
index 9f3b3fe..f19fa5d 100644
--- a/tools.json
+++ b/tools.json
@@ -25,5 +25,19 @@
 			"https://ece.uwaterloo.ca/~aplevich/dpic": "Get DPIC from here"
 		},
 		"Example": ".PS\n\nbox \"foo\"; arrow ->; box \"bar\"\n\n.PE"
+	},
+	{
+		"Name":    "povray",
+		"Cmd":     "povray",
+		"Args":    ["+O-", "-D", "+A0.9", "+R3"], 
+		"Suffix":  ".pov",
+		"NeedsFile": true,
+		"ContentType": "img/png",
+		"Description": "Povray, raytracer",
+		"BgColor": "Orange",
+		"Documentation": {
+			"http://povray.org/documentation/3.7.0/index.html": "POV-Ray for Unix"
+		},
+		"Example": "#include \"colors.inc\"\n#include \"woods.inc\"\n#include \"glass.inc\"\ncylinder {\n\t<-2,-2,0.5>, <-2,1,0.5>, 1\n\tpigment {color Red}\n}\nsphere {\n\t<0,1,1>, 1\n\tpigment {color Blue }\n}\nbox {\n\t<-3,-1,-1>, <1,-0.5, 2>\n\tpigment {\n\t\tCol_Glass_Winebottle\n\t}\n}\nbackground   { color Gray60 }\nlight_source {<0, 5, -3>   color White }\nlight_source {<-2, 2, 0.5> color Yellow }\ncamera {\n\tlocation <0, 2, -6>\n\tangle 50 right x\n\tlook_at\n\t<-1, 0, 0>\n}\n"
 	}
 ]