diff --git a/.gitignore b/.gitignore
index c00a739..040084b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 # Ignore binaries
 bin/
+*.o
diff --git a/src/main.c b/src/main.c
index c74f5e6..62d2c2f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,16 +1,46 @@
+/**
+ * CoinToss, a probability simulator.
+ * Copyright (C) 2014 Nicolás A. Ortega
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 
 char version[7] = "v0.1";
 
+void printCopyright();
+void printAllCopyright();
+void printWarranty();
+
 int main(int argc, char **argv) {
-	printf("Welcome to Coin Toss %s\n", version);
 	if(argc < 2 || argc > 3) {
 		printf("Usage: %s [trials]\n", argv[0]);
 		return 1;
 	}
 
+	if(strcmp(argv[1], "-c") == 0) {
+		printAllCopyright();
+		return 0;
+	} else if(strcmp(argv[1], "-w") == 0) {
+		printWarranty();
+		return 0;
+	}
+
+	printCopyright();
+
 	int trials = atoi(argv[1]);
 	int heads = 0;
 	int tails = 0;
@@ -28,3 +58,36 @@ int main(int argc, char **argv) {
 	printf("Tails: %i\n", tails);
 	return 0;
 }
+
+void printCopyright() {
+	printf("CoinToss %s Copyright (C) 2014  Nicolás A. Ortega\n\
+		This program comes with ABSOLUTELY NO WARRANTY; for details use `-w'.\n\
+		This is free software, and you are welcome to redistribute it\n\
+		under certain conditions; use `-c' for details.\n\n", version);
+}
+
+void printAllCopyright() {
+	printf("CoinToss, a probability simulator.\n\
+		Copyright (C) 2014 Nicolás A. Ortega\n\n\
+		This program is free software: you can redistribute it and/or modify\n\
+		it under the terms of the GNU General Public License as published by\n\
+		the Free Software Foundation, either version 3 of the License, or\n\
+		(at your option) any later version.\n\n\
+		This program is distributed in the hope that it will be useful,\n\
+		but WITHOUT ANY WARRANTY; without even the implied warranty of\n\
+		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n\
+		GNU General Public License for more details.\n\n\
+		You should have received a copy of the GNU General Public License\n\
+		along with this program.  If not, see <http://www.gnu.org/licenses/>.\n");
+}
+
+void printWarranty() {
+	printf("  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY\n\
+		APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT\n\
+		HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM \"AS IS\" WITHOUT WARRANTY\n\
+		OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,\n\
+		THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR\n\
+		PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM\n\
+		IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF\n\
+		ALL NECESSARY SERVICING, REPAIR OR CORRECTION.\n");
+}