diff --git a/rhubarb/CMakeLists.txt b/rhubarb/CMakeLists.txt
index 41507c3..17b257f 100644
--- a/rhubarb/CMakeLists.txt
+++ b/rhubarb/CMakeLists.txt
@@ -360,6 +360,8 @@ target_link_libraries(rhubarb-core
 
 # ... rhubarb-exporters
 add_library(rhubarb-exporters
+	src/exporters/DatExporter.cpp
+	src/exporters/DatExporter.h
 	src/exporters/Exporter.h
 	src/exporters/exporterTools.cpp
 	src/exporters/exporterTools.h
diff --git a/rhubarb/src/exporters/DatExporter.cpp b/rhubarb/src/exporters/DatExporter.cpp
new file mode 100644
index 0000000..cf3bf3f
--- /dev/null
+++ b/rhubarb/src/exporters/DatExporter.cpp
@@ -0,0 +1,72 @@
+#include "DatExporter.h"
+#include "animation/targetShapeSet.h"
+#include <boost/lexical_cast.hpp>
+
+using std::chrono::duration;
+using std::chrono::duration_cast;
+using std::string;
+
+DatExporter::DatExporter(const ShapeSet& targetShapeSet, double frameRate, bool convertToPrestonBlair) :
+	frameRate(frameRate),
+	convertToPrestonBlair(convertToPrestonBlair),
+	prestonBlairShapeNames {
+		{ Shape::A, "MBP" },
+		{ Shape::B, "etc" },
+		{ Shape::C, "E" },
+		{ Shape::D, "AI" },
+		{ Shape::E, "O" },
+		{ Shape::F, "U" },
+		{ Shape::G, "FV" },
+		{ Shape::H, "L" },
+		{ Shape::X, "rest" },
+	}
+{
+	// Animation works with a fixed frame rate of 100.
+	// Downsampling to much less than 25 fps may result in dropped frames.
+	// Upsampling to more than 100 fps doesn't make sense.
+	const double minFrameRate = 24.0;
+	const double maxFrameRate = 100.0;
+
+	if (frameRate < minFrameRate || frameRate > maxFrameRate) {
+		throw std::runtime_error(fmt::format("Frame rate must be between {} and {} fps.", minFrameRate, maxFrameRate));
+	}
+
+	if (convertToPrestonBlair) {
+		for (Shape shape : targetShapeSet) {
+			if (prestonBlairShapeNames.find(shape) == prestonBlairShapeNames.end()) {
+				throw std::runtime_error(fmt::format("Mouth shape {} cannot be converted to Preston Blair shape names."));
+			}
+		}
+	}
+}
+
+void DatExporter::exportAnimation(const ExporterInput& input, std::ostream& outputStream) {
+	outputStream << "MohoSwitch1" << "\n";
+
+	// Output shapes with start times
+	int lastFrameNumber = 0;
+	for (auto& timedShape : input.animation) {
+		const int frameNumber = toFrameNumber(timedShape.getStart());
+		if (frameNumber == lastFrameNumber) continue;
+
+		const string shapeName = toString(timedShape.getValue());
+		outputStream << frameNumber << " " << shapeName << "\n";
+		lastFrameNumber = frameNumber;
+	}
+
+	// Output closed mouth with end time
+	int frameNumber = toFrameNumber(input.animation.getRange().getEnd());
+	if (frameNumber == lastFrameNumber) ++frameNumber;
+	const string shapeName = toString(convertToTargetShapeSet(Shape::X, input.targetShapeSet));
+	outputStream << frameNumber << " " << shapeName << "\n";
+}
+
+string DatExporter::toString(Shape shape) const {
+	return convertToPrestonBlair
+		? prestonBlairShapeNames.at(shape)
+		: boost::lexical_cast<std::string>(shape);
+}
+
+int DatExporter::toFrameNumber(centiseconds time) const {
+	return 1 + static_cast<int>(frameRate * duration_cast<duration<double>>(time).count());
+}
diff --git a/rhubarb/src/exporters/DatExporter.h b/rhubarb/src/exporters/DatExporter.h
new file mode 100644
index 0000000..af6284e
--- /dev/null
+++ b/rhubarb/src/exporters/DatExporter.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include "Exporter.h"
+#include "core/Shape.h"
+#include <map>
+#include <string>
+
+// Exporter for Moho's switch data file format
+class DatExporter : public Exporter {
+public:
+	DatExporter(const ShapeSet& targetShapeSet, double frameRate, bool convertToPrestonBlair);
+	void exportAnimation(const ExporterInput& input, std::ostream& outputStream) override;
+
+private:
+	int toFrameNumber(centiseconds time) const;
+	std::string toString(Shape shape) const;
+
+	double frameRate;
+	bool convertToPrestonBlair;
+	std::map<Shape, std::string> prestonBlairShapeNames;
+};
diff --git a/rhubarb/src/rhubarb/ExportFormat.cpp b/rhubarb/src/rhubarb/ExportFormat.cpp
index 6619f3f..9e15e39 100644
--- a/rhubarb/src/rhubarb/ExportFormat.cpp
+++ b/rhubarb/src/rhubarb/ExportFormat.cpp
@@ -13,6 +13,7 @@ string ExportFormatConverter::getTypeName() {
 
 EnumConverter<ExportFormat>::member_data ExportFormatConverter::getMemberData() {
 	return member_data {
+		{ ExportFormat::Dat,		"dat" },
 		{ ExportFormat::Tsv,		"tsv" },
 		{ ExportFormat::Xml,		"xml" },
 		{ ExportFormat::Json,		"json" }
diff --git a/rhubarb/src/rhubarb/ExportFormat.h b/rhubarb/src/rhubarb/ExportFormat.h
index 1ff9392..8591c04 100644
--- a/rhubarb/src/rhubarb/ExportFormat.h
+++ b/rhubarb/src/rhubarb/ExportFormat.h
@@ -3,6 +3,7 @@
 #include "tools/EnumConverter.h"
 
 enum class ExportFormat {
+	Dat,
 	Tsv,
 	Xml,
 	Json
diff --git a/rhubarb/src/rhubarb/main.cpp b/rhubarb/src/rhubarb/main.cpp
index e873422..4e512a9 100644
--- a/rhubarb/src/rhubarb/main.cpp
+++ b/rhubarb/src/rhubarb/main.cpp
@@ -18,6 +18,7 @@
 #include "tools/textFiles.h"
 #include "lib/rhubarbLib.h"
 #include "ExportFormat.h"
+#include "exporters/DatExporter.h"
 #include "exporters/TsvExporter.h"
 #include "exporters/XmlExporter.h"
 #include "exporters/JsonExporter.h"
@@ -82,8 +83,15 @@ unique_ptr<Recognizer> createRecognizer(RecognizerType recognizerType) {
 	}
 }
 
-unique_ptr<Exporter> createExporter(ExportFormat exportFormat) {
+unique_ptr<Exporter> createExporter(
+	ExportFormat exportFormat,
+	const ShapeSet& targetShapeSet,
+	double datFrameRate,
+	bool datUsePrestonBlair
+) {
 	switch (exportFormat) {
+		case ExportFormat::Dat:
+			return make_unique<DatExporter>(targetShapeSet, datFrameRate, datUsePrestonBlair);
 		case ExportFormat::Tsv:
 			return make_unique<TsvExporter>();
 		case ExportFormat::Xml:
@@ -172,6 +180,16 @@ int main(int platformArgc, char* platformArgv[]) {
 		false, string(), "string", cmd
 	);
 
+	tclap::SwitchArg datUsePrestonBlair(
+		"", "datUsePrestonBlair", "Only for dat exporter: uses the Preston Blair mouth shape names.",
+		cmd, false
+	);
+
+	tclap::ValueArg<double> datFrameRate(
+		"", "datFrameRate", "Only for dat exporter: the desired frame rate.",
+		false, 24.0, "number", cmd
+	);
+
 	auto exportFormats = vector<ExportFormat>(ExportFormatConverter::get().getValues());
 	tclap::ValuesConstraint<ExportFormat> exportFormatConstraint(exportFormats);
 	tclap::ValueArg<ExportFormat> exportFormat(
@@ -222,6 +240,13 @@ int main(int platformArgc, char* platformArgv[]) {
 		path inputFilePath(inputFileName.getValue());
 		ShapeSet targetShapeSet = getTargetShapeSet(extendedShapes.getValue());
 
+		unique_ptr<Exporter> exporter = createExporter(
+			exportFormat.getValue(),
+			targetShapeSet,
+			datFrameRate.getValue(),
+			datUsePrestonBlair.getValue()
+		);
+
 		logging::log(StartEntry(inputFilePath));
 		logging::debugFormat("Command line: {}",
 			join(args | transformed([](string arg) { return fmt::format("\"{}\"", arg); }), " "));
@@ -246,7 +271,6 @@ int main(int platformArgc, char* platformArgv[]) {
 			logging::info("Done animating.");
 
 			// Export animation
-			unique_ptr<Exporter> exporter = createExporter(exportFormat.getValue());
 			optional<boost::filesystem::ofstream> outputFile;
 			if (outputFileName.isSet()) {
 				outputFile = boost::in_place(outputFileName.getValue());