diff --git a/libtelnet.c b/libtelnet.c
new file mode 100644
index 0000000..b148d8e
--- /dev/null
+++ b/libtelnet.c
@@ -0,0 +1,162 @@
+#include "libtelnet.h"
+
+/* initialize a telnet state tracker */
+void libtelnet_init(struct libtelnet_t *telnet) {
+	telnet->state = LIBTELNET_TEXT;
+	telnet->buffer = 0;
+	telnet->size = 0;
+	telnet->length = 0;
+}
+
+/* free up any memory allocated by a state tracker */
+void libtelnet_close(struct libtelnet_t *telnet) {
+	if (telnet->buffer) {
+		free(telnet->buffer);
+		telnet->buffer = 0;
+	}
+}
+
+/* push a single byte into the state tracker */
+void libtelnet_push_byte(struct libtelnet_t *telnet, unsigned char byte,
+		void *user_data) {
+	switch (telnet->state) {
+	/* regular data */
+	case LIBTELNET_STATE_TEXT:
+		/* enter IAC state on IAC byte */
+		if (byte == LIBTELNET_IAC)
+			telnet->state = LIBTELNET_STATE_IAC;
+		/* regular input byte */
+		else
+			telnet->input_cb(telnet, byte, user_data);
+		break;
+	case LIBTELNET_STATE_IAC:
+		switch (byte) {
+		/* subrequest */
+		case LIBTELNET_SB:
+			telnet->state = LIBTELNET_STATE_SB;
+			break;
+		/* negotiation commands */
+		case LIBTELNET_WILL:
+			telnet->state = LIBTELNET_STATE_WILL;
+			break;
+		case LIBTELNET_WONT:
+			telnet->state = LIBTELNET_STATE_WONT;
+			break;
+		case LIBTELNET_DO:
+			telnet->state = LIBTELNET_STATE_DO;
+			break;
+		case LIBTELNET_DONT:
+			telnet->state = LIBTELNET_STATE_DONT;
+			break;
+		/* IAC escaping */
+		case LIBTELNET_IAC:
+			telbet->input_cb(telnet, LIBTELNET_IAC, user_data);
+			libtelnet->state = LIBTELNET_STATE_TEXT;
+			break;
+		/* some other command */
+		default:
+			telnet->command_cb(telnet, byte, user_data);
+			telnet->state = LIBTELNET_STATE_TEXT;
+		}
+		break;
+	/* DO negotiation */
+	case LIBTELNET_STATE_DO:
+		telnet->negotiate_cb(telnet, LIBTELNET_DO, byte, user_data);
+		telnet->state = LIBTELNET_STATE_TEXT;
+		break;
+	case LIBTELNET_STATE_DONT:
+		telnet->negotiate_cb(telnet, LIBTELNET_DONT, byte, user_data);
+		telnet->state = LIBTELNET_STATE_TEXT;
+		break;
+	case LIBTELNET_STATE_WILL:
+		telnet->negotiate_cb(telnet, LIBTELNET_WILL, byte, user_data);
+		telnet->state = LIBTELNET_STATE_TEXT;
+		break;
+	case LIBTELNET_STATE_WONT:
+		telnet->negotiate_cb(telnet, LIBTELNET_WONT, byte, user_data);
+		telnet->state = LIBTELNET_STATE_TEXT;
+		break;
+	/* subrequest -- buffer bytes until end request */
+	case LIBTELNET_STATE_SB:
+		/* IAC command in subrequest -- either IAC SE or IAC IAC */
+		if (byte == LIBTELNET_IAC) {
+			telnet->state = LIBTELNET_STATE_SB_IAC;
+		} else {
+			/* FIXME: buffer byte */
+		}
+		break;
+	/* IAC escaping inside a subrequest */
+	case LIBTELNET_STATE_SB_IAC:
+		switch (byte) {
+		/* end subrequest */
+		case LIBTELNET_SE:
+			/* FIXME: process */
+			telnet->state = LIBTELNET_STATE_TEXT;
+			break;
+		/* escaped IAC byte */
+		case LIBTELNET_IAC:
+			/* FIXME: buffer byte */
+			telnet->state = LIBTELNET_STATE_SB;
+			break;
+		/* something else -- protocol error */
+		default:
+			telnet->error_cb(telnet, LIBTELNET_ERROR_PROTOCOL, user_data);
+			telnet->state = LIBTELNET_STATE_TEXT;
+			break;
+		}
+		break;
+	}
+}
+
+/* push a byte buffer into the state tracker */
+void libtelnet_push_buffer(struct libtelnet_t *telnet, unsigned char *buffer,
+		size_t size, void *user_data) {
+	size_t i;
+	for (i = 0; i != size; ++i)
+		libtelnet_push_byte(telnet, buffer[i], user_data);
+}
+
+/* send an iac command */
+void libtelnet_send_command(struct libtelnet_t *telnet, unsigned char cmd,
+		void *user_data) {
+	unsigned char bytes[2] = { IAC, cmd };
+	telnet->output_cb(telnet, bytes, 2, user_data);
+}
+
+/* send negotiation */
+void libtelnet_send_negotiate(struct libtelnet_t *telnet, unsigned char cmd,
+		unsigned char opt, void *user_data) {
+	unsigned char bytes[3] = { IAC, cmd, opt };
+	telnet->output_cb(telnet, bytes, 3, user_data);
+}
+
+/* send non-command data (escapes IAC bytes) */
+void libtelnet_send_data(struct libtelnet_t *telnet, unsigned char *buffer,
+		size_t size, void *user_data) {
+	size_t i, l;
+	for (l = i = 0; i != size; ++i) {
+		/* dump prior portion of text, send escaped bytes */
+		if (buffer[i] == LIBTELNET_IAC) {
+			/* dump prior text if any */
+			if (i != l)
+				telnet->output_cb(telnet, buffer + l, i - l, user_data);
+			l = i + 1;
+
+			/* send escape */
+			libtelnet_send_command(telnet, LIBTELNET_IAC, user_data);
+		}
+	}
+
+	/* send whatever portion of buffer is left */
+	if (i != l)
+		telnet->output_cb(telnet, buffer + l, i - l, user_data);
+}
+
+/* send sub-request */
+void libtelnet_send_subrequest(struct libtelnet_t *telnet, unsigned char type,
+		unsigned char *buffer, size_t size, void *user_data)  {
+	libtelnet_send_command(telnet, SB, user_data);
+	libtelnet_send_data(telnet, &type, 1, user_data);
+	libtelnet_send_data(telnet, buffer, size, user_data);
+	libtelnet_send_command(telnet, SE, user_data);
+}
diff --git a/libtelnet.h b/libtelnet.h
new file mode 100644
index 0000000..a3cba24
--- /dev/null
+++ b/libtelnet.h
@@ -0,0 +1,111 @@
+/*
+ * The author or authors of this code dedicate any and all copyright interest
+ * in this code to the public domain. We make this dedication for the benefit
+ * of the public at large and to the detriment of our heirs and successors. We
+ * intend this dedication to be an overt act of relinquishment in perpetuity of
+ * all present and future rights to this code under copyright law. 
+ */
+
+/* sub request buffer size increment (defualt 4K) */
+#define LIBTELNET_BUFFER_SIZE (4 * 1024)
+/* sub request buffer size (default 16K) */
+#define LIBTELNET_BUFFER_SIZE_MAX (16 * 1024)
+
+/* telnet special values */
+#define LIBTELNET_IAC 255
+#define LIBTELNET_DONT 254
+#define LIBTELNET_DO 253
+#define LIBTELNET_WONT 252
+#define LIBTELNET_WILL 251
+#define LIBTELNET_SB 250
+#define LIBTELNET_SE 240
+
+/* telnet options */
+#define LIBTELNET_OPTION_BINARY 0
+#define LIBTELNET_OPTION_ECHO 1
+#define LIBTELNET_OPTION_NAWS 31
+#define LIBTELNET_OPTION_ZMP 93
+
+/* telnet states */
+enum libtelnet_state_t {
+	LIBTELNET_STATE_TEXT = 0,
+	LIBTELNET_STATE_IAC,
+	LIBTELNET_STATE_DO,
+	LIBTELNET_STATE_DONT,
+	LIBTELNET_STATE_WILL,
+	LIBTELNET_STATE_WONT,
+	LIBTELNET_STATE_SB,
+	LIBTELNET_STATE_SB_IAC,
+};
+
+/* error codes */
+enum libtelnet_error_t {
+	LIBTELNET_ERROR_OK = 0,
+	LIBTELNET_ERROR_OVERFLOW, /* input exceeds buffer size */
+	LIBTELNET_ERROR_PROTOCOL, /* invalid sequence of special bytes */
+	LIBTELNET_ERROR_UNKNOWN, /* some crazy unexplainable unknown error */
+};
+
+/* callback prototypes */
+typedef (void)(*libtelnet_input)(struct libtelnet_t *telnet, unsigned char
+		byte, void *user_data);
+typedef (void)(*libtelnet_output)(struct libtelnet_t *telnet, unsigned char
+		byte, void *user_data);
+typedef (void)(*libtelnet_command)(struct libtelnet_t *telnet, unsigned char
+		cmd, void *user_data);
+typedef (void)(*libtelnet_negotiate)(struct libtelnet_t *telnet, unsigned char
+		cmd, unsigned char opt, void *user_data);
+typedef (void)(*libtelnet_subrequest)(struct libtelnet_t *telnet, unsigned char
+		cmd, unsigned char type, unsigned char *data, size_t size,
+		void *user_data);
+typedef (void)(*libtelnet_error)(struct libtelnet_t *telnet,
+		enum libtelnet_error_t error, void *user_data);
+
+/* state tracker */
+struct libtelnet_t {
+	/* current state */
+	enum libtelnet_state_t state;
+	/* sub-request buffer */
+	char *buffer;
+	/* current size of the buffer */
+	size_t size;
+	/* length of data in the buffer */
+	size_t length;
+
+	/* callbacks */
+	libtelnet_input input_cb;
+	libtelnet_output output_cb;
+	libtelnet_command command_cb;
+	libtelnet_negotiate negotiate_cb;
+	libtelnet_subrequest subrequest_cb;
+};
+
+/* initialize a telnet state tracker */
+void libtelnet_init(struct libtelnet_t *telnet);
+
+/* free up any memory allocated by a state tracker */
+void libtelnet_close(struct libtelnet_t *telnet);
+
+/* push a single byte into the state tracker */
+void libtelnet_push_byte(struct libtelnet_t *telnet, unsigned char byte,
+	void *user_data);
+
+/* push a byte buffer into the state tracker */
+void libtelnet_push_buffer(struct libtelnet_t *telnet, unsigned char *buffer,
+	size_t size, void *user_data);
+
+/* send an iac command */
+void libtelnet_send_command(struct libtelnet_t *telnet, unsigned char cmd,
+	void *user_data);
+
+/* send negotiation */
+void libtelnet_send_negotiate(struct libtelnet_t *telnet, unsigned char cmd,
+	unsigned char opt, void *user_data);
+
+/* send non-command data (escapes IAC bytes) */
+void libtelnet_send_data(struct libtelnet_t *telnet, unsigned char *buffer,
+	size_t size, void *user_data);
+
+/* send sub-request */
+void libtelnet_send_subrequest(struct libtelnet_t *telnet, unsigned char type,
+	unsigned char *buffer, size_t size, void *user_data);