diff --git a/.gitignore b/.gitignore
index 2023dfa..503d9e0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,4 +19,5 @@ bin/sysexits
 build/*
 include/sysexits.h
 lib/*.o
+rot13/rot13
 src/*.o
diff --git a/Makefile b/Makefile
index ef93e1d..91fac8e 100644
--- a/Makefile
+++ b/Makefile
@@ -118,11 +118,11 @@ roll_stdio.o: lib/libio.h src/roll.c sysexits
 roll_stdio: libio roll_stdio.o
 	$(CC) $(CFLAGS) -o bin/roll_stdio build/libio.o build/roll_stdio.o
 
-rot13.o: libio sysexits src/rot13.c
-	$(CC) $(CFLAGS) -c -o build/rot13.o src/rot13.c
+rot13: rot13/rot13
+	mv rot13/rot13 bin/rot13
 
-rot13: libio rot13.o
-	$(CC) $(CFLAGS) -o bin/rot13 build/libio.o build/rot13.o
+rot13/rot13: sysexits rot13/rot13.c rot13/Makefile
+	$(MAKE) -C rot13 sane
 
 rldecode.o: sysexits src/runlength.c
 	$(CC) $(CFLAGS) -Df=decode -c -o build/rldecode.o src/runlength.c
diff --git a/rot13/Makefile b/rot13/Makefile
new file mode 100644
index 0000000..6a0bab6
--- /dev/null
+++ b/rot13/Makefile
@@ -0,0 +1,26 @@
+all: rot13
+
+clean:
+	rm -rf ../dist/rot13 ../dist/rot13.tar ../dist/rot13.tar.gz rot13
+
+dist: ../dist/rot13.tar.gz
+
+sane: rot13.c ../include/sysexits.h
+	$(CC) -DDONT_USE_SYSTEM_SYSEXITS -o rot13 rot13.c
+rot13: rot13.c
+	$(CC) -o rot13 rot13.c
+
+../dist/rot13: rot13
+	mkdir -p ../dist/rot13.tmp/bin/
+	cp rot13 ../dist/rot13.tmp/bin/rot13
+	mv ../dist/rot13.tmp ../dist/rot13
+
+../dist/rot13.tar: ../dist/rot13
+	cd ../dist/rot13 && pax -w -x ustar . >../rot13.tar.tmp
+	mv ../dist/rot13.tar.tmp ../dist/rot13.tar
+
+../dist/rot13.tar.gz: ../dist/rot13.tar
+	gzip -c <../dist/rot13.tar >../dist/rot13.tar.gz.tmp
+	mv ../dist/rot13.tar.gz.tmp ../dist/rot13.tar.gz
+
+.PHONY: all clean sane
diff --git a/rot13/rot13.c b/rot13/rot13.c
new file mode 100644
index 0000000..08915be
--- /dev/null
+++ b/rot13/rot13.c
@@ -0,0 +1,68 @@
+#include <stddef.h> /* stdin, stdout */
+
+/* When rot13(1) is a part of ~trinity/src, which doesn't assume the system has
+ * <sysexits.h> and generates it out of a table. */
+#ifdef DONT_USE_SYSTEM_SYSEXITS
+#	include "../include/sysexits.h" /* EX_OK, EX_USAGE */
+#else
+#	include <sysexits.h> /* EX_OK, EX_USAGE */
+#endif
+
+#ifdef U_UNICODE_VERSION /* libicu Unicode support */
+#	define CHARACTER UChar32
+
+#	include <uchar.h> /* u_isupper(3) */
+#	define ISUPPER u_isupper
+
+#	include <ustdio.h> /* U_EOF */
+#	define ENDOFFILE U_EOF
+#else /* ifdef U_UNICODE_VERSION */
+#	define CHARACTER int
+
+#	include <ctype.h> /* isalpha(3), isupper(3) */
+#	define ISALPHA isalpha
+#	define ISUPPER isupper
+
+#	include <stdio.h> /* getc(3), putc(3) */
+#	define ENDOFFILE EOF
+#	define GETC getc
+#	define PUTC putc
+#endif /* ifdef U_UNICODE_VERSION */
+
+static char *program_name = "rot13";
+
+// /* Assumes this is a character in the provided glyph system.
+//  * Probably not Unicode-capable but doesn't assume Alphabet.
+//  * Returns `c` rotated around `a` by `r` characters. */
+// #include <string.h> /* strchr(3), strlen(3) */
+// static int
+// caesar(char c, int r, const char *a){
+// 	return a[(strchr(a, c) - a + r) % strlen(a)];
+// }
+
+/* Or... make some static arrays of the alphabet * 1.5, so c + '\0' + 13 is
+ * always a valid index and always reflects the correct rotation (13 places).
+ */
+static char alpha_upper[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLM";
+static char alpha_lower[] = "abcdefghijklmnopqrstuvwxyzabcdefghijklm";
+
+int main(int argc, char *argv[]){
+	char *a; /* easier than doing freaky math */
+	CHARACTER c;
+
+	if(argc > 1){
+		fprintf(stderr, "Usage: %s\n",
+			argv[0] == NULL ? program_name : argv[0]
+		);
+		return EX_USAGE;
+	}
+
+	while((c = getc(stdin)) != EOF)
+		if(isalpha(c)){
+			a = isupper(c) ? alpha_upper : alpha_lower;
+			putc(a[c - a[0] + 13], stdout);
+		}else
+			putc(c, stdout);
+
+	return EX_OK;
+}
diff --git a/src/rot13.c b/src/rot13.c
deleted file mode 100644
index cc99dc1..0000000
--- a/src/rot13.c
+++ /dev/null
@@ -1,41 +0,0 @@
-#include <ctype.h> /* isalpha(3), isupper(3) */
-#include <stdio.h> /* getc(3), putc(3) */
-#include <stddef.h> /* stdin, stdout, EOF */
-#include <string.h> /* strchr(3), strlen(3) */
-#include <sysexits.h> /* EX_OK, EX_USAGE */
-#include <unistd.h> /* write(2) */
-#include "libio.h" /* fdputs(3) */
-#include "usefulmacros.h" /* ARRAYLEN */
-
-static char *program_name = "rot13";
-
-/* Assumes this is a character in the provided glyph system.
- * Probably not Unicode-capable but doesn't assume Alphabet.
- * Returns `c` rotated around `a` by `r` characters. */
-static int
-caesar(char c, int r, const char *a){
-	return a[(strchr(a, c) - a + r) % strlen(a)];
-}
-
-/* It's faster to assume Alphabet. */
-static char alpha_upper[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLM";
-static char alpha_lower[] = "abcdefghijklmnopqrstuvwxyzabcdefghijklm";
-
-int main(int argc, char *argv[]){
-	char *a;
-	int c;
-
-	if(argc > 1){
-		write(2, "Usage: ", 7);
-		fdputs(2, argv[0] == NULL ? program_name : argv[0]);
-		return EX_USAGE;
-	}
-
-	while((c = getc(stdin)) != EOF){
-		if(isalpha(c)){
-			a = isupper(c) ? alpha_upper : alpha_lower;
-			putc(a[c - a[0] + 13], stdout);
-		}else
-			putc(c, stdout);
-	}
-}
diff --git a/src/xml.c b/src/xml.c
deleted file mode 100644
index 18ed7ea..0000000
--- a/src/xml.c
+++ /dev/null
@@ -1,113 +0,0 @@
-#include <ctype.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include "arraylen.h"
-#include "bool.h"
-
-#define TAGSTART '<'
-#define TAGEND   '>'
-#define ETAG     '/'
-
-#define LF       '\n'
-
-/*
-  start-tag    end-tag
-    |            |
-    V            V
-  <TAG>CONTENT</TAG>
-  ^   ^        ^
-  |   |        |
-  |   TAGEND   ETAG
-  |
-  TAGSTART
-
-  empty-element tag
-    |
-    | optional whitespace
-    | |
-    | | TAGEND
-    | | |
-    V V V
-  <TAG />
-  ^    ^
-  |    |
-  |    ETAG
-  |
-  TAGSTART
-
-*/
-
-/* a lot of this program's design is weird and kind of overengineered.
-   this is to drastically limit the memory used. */
-
-
-enum state{
-	error = -1, /* for future use */
-	init = 0, /* waiting for a root tag */
-	starttagreading,
-	tagreading,
-	eetagreading, /* throw away everything until state change */
-	endtagreading,
-	contentreading /* printing */
-};
-
-void
-usage(char *name){
-	fprintf(stdout, "Usage: %s [tag...]\n", name);
-	return;
-}
-
-int main(int argc, char *argv[]){
-	if(argc < 2){
-		usage(argv[0]);
-		return 0;
-	}
-
-	bool enable = 0;
-	char c;
-	int linenumber = 0;
-	enum state s = init;
-	FILE *input = stdin;
-	FILE *output = stdout;
-	int level = 1; /* 1-indexed because args start at 1 */
-	size_t p = 0;
-
-	while(c = getc(input) != EOF){
-		if(c == LF){
-			++linenumber;
-			continue;
-		}
-		switch(s){
-		case init:
-			if(c == TAGSTART)
-				s = starttagreading;
-			break;
-		case starttagreading:
-			if(c == ETAG)
-				s = endtagreading;
-			else if(!isblank(c))
-				s = tagreading;
-			break;
-		case tagreading:
-			if(c == ETAG)
-				s = eetagreading;
-			break;
-		/* case eetagreading: */
-		case endtagreading:
-			if(c == ETAG)
-				fprintf(stderr, "%s:%d: Stray \'%c\' in an end tag?\n", argv[0], linenumber, ETAG);
-			break;
-		case contentreading:
-			if(enable)
-				putc(c, output);
-			else if(c == TAGSTART)
-			s = starttagreading;
-			else if(c == TAGEND)
-				fprintf(stderr, "%s:%d: Possible state error or XML syntax error; \'%c\' in mode contentreading\n", argv[0], linenumber, TAGEND);
-			break;
-		}
-	}
-
-	return 0;
-}