diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..8a1ab67
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,13 @@
+Copyright (c) 2020 David Oberhollenzer <goliath@infraroot.at>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
diff --git a/shader.c b/shader.c
index b77447b..2cad446 100644
--- a/shader.c
+++ b/shader.c
@@ -1,3 +1,9 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * shader.c
+ *
+ * Copyright (C) 2022 David Oberhollenzer <goliath@infraroot.at>
+ */
 #include "shadermeh.h"
 
 /* stub vertex shader */
diff --git a/shadermeh.c b/shadermeh.c
index bd2cae7..f02054c 100644
--- a/shadermeh.c
+++ b/shadermeh.c
@@ -1,3 +1,9 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * shadermeh.c
+ *
+ * Copyright (C) 2022 David Oberhollenzer <goliath@infraroot.at>
+ */
 #include "shadermeh.h"
 
 static GLfloat vertex_buffer[] = {
diff --git a/shadermeh.h b/shadermeh.h
index d7bb018..d8b7f46 100644
--- a/shadermeh.h
+++ b/shadermeh.h
@@ -1,3 +1,9 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * shadermeh.h
+ *
+ * Copyright (C) 2022 David Oberhollenzer <goliath@infraroot.at>
+ */
 #ifndef SHADERMEH_H
 #define SHADERMEH_H
 
diff --git a/window.c b/window.c
index 496f6c0..39333cf 100644
--- a/window.c
+++ b/window.c
@@ -1,3 +1,9 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * window.c
+ *
+ * Copyright (C) 2022 David Oberhollenzer <goliath@infraroot.at>
+ */
 #include "shadermeh.h"
 
 #ifndef GLX_ARB_create_context