diff --git a/build/targets.mak b/build/targets.mak
index 68ce3de04..c770b34bf 100644
--- a/build/targets.mak
+++ b/build/targets.mak
@@ -41,3 +41,58 @@ endef
 -include build/targets.$(PLATFORM).mak
 
 $(foreach extension,$(HANDY_TARGETS_EXTENSIONS),$(foreach executable,$(HANDY_TARGETS),$(eval $(call handy_target_rule,$(executable),$(extension)))))
+
+define source_emsdk
+source ~/emsdk/emsdk_env.sh > /dev/null
+endef
+
+ANDROID_GRADLE_KEYSTORE:= $(wildcard ~/.gradle/google-play-upload.keystore)
+ANDROID_GRADLE_PROPERTIES:= $(wildcard ~/.gradle/gradle.properties)
+IOS_MOBILE_PROVISION:= $(wildcard ~/Downloads/NumWorks_Graphing_Calculator_Distribution.mobileprovision)
+
+MISSING_FILES=1
+
+ifneq "$(and $(ANDROID_GRADLE_KEYSTORE),$(ANDROID_GRADLE_PROPERTIES))" ""
+ifneq "$(IOS_MOBILE_PROVISION)" ""
+  MISSING_FILES=0
+endif
+endif
+
+.PHONY: stable_release
+ifeq ($(MISSING_FILES),1)
+stable_release:
+	@echo "Some required files for app signing are missing among: ~/.gradle/google-play-upload.keystore, ~/.gradle/gradle.properties or ~/Downloads/NumWorks_Graphing_Calculator_Distribution.mobileprovision."
+else
+stable_release:
+	$(Q) rm -rf output/stable_release
+	$(Q) mkdir -p output/stable_release
+	$(Q) echo "BUILD_FIRMWARE    DEVICE N0110"
+	$(Q) make clean
+	$(Q) make -j8 epsilon.official.onboarding.dfu
+	$(Q) cp output/release/device/n0110/epsilon.official.onboarding.dfu output/stable_release/epsilon.device.n0110.dfu
+	$(Q) echo "BUILD_FIRMWARE    DEVICE N0100"
+	$(Q) make MODEL=n0100 clean
+	$(Q) make -j8 MODEL=n0100 epsilon.official.onboarding.dfu
+	$(Q) cp output/release/device/n0100/epsilon.official.onboarding.dfu output/stable_release/epsilon.device.n0100.dfu
+	$(Q) echo "BUILD_FIRMWARE    SIMULATOR WEB ZIP"
+	$(Q) make -j8 DEBUG=0 PLATFORM=simulator TARGET=web clean
+	$(Q) $(call source_emsdk); make -j8 DEBUG=0 PLATFORM=simulator TARGET=web output/release/simulator/web/simulator.official.zip
+	$(Q) cp output/release/simulator/web/simulator.official.zip output/stable_release/simulator.web.zip
+	$(Q) echo "BUILD_FIRMWARE    SIMULATOR WEB JS"
+	$(Q) $(call source_emsdk); make -j8 DEBUG=0 PLATFORM=simulator TARGET=web epsilon.official.js
+	$(Q) cp output/release/simulator/web/epsilon.official.js output/stable_release/epsilon.js
+	$(Q) echo "BUILD_FIRMWARE    SIMULATOR WEB PYTHON JS"
+	$(Q) make -j8 DEBUG=0 PLATFORM=simulator TARGET=web clean
+	$(Q) $(call source_emsdk); make -j8 DEBUG=0 PLATFORM=simulator TARGET=web EPSILON_GETOPT=1 EPSILON_APPS=code epsilon.official.js
+	$(Q) cp output/release/simulator/web/epsilon.official.js output/stable_release/epsilon.python.js
+	$(Q) echo "BUILD_FIRMWARE    SIMULATOR ANDROID"
+	$(Q) make -j8 PLATFORM=simulator TARGET=android clean
+	$(Q) make -j8 PLATFORM=simulator TARGET=android epsilon.official.apk
+#TODO: what are the files made by gradle?
+#	$(Q) cp output/release/simulator/android/epsilon.official.apk output/stable_release/epsilon.apk
+	$(Q) echo "BUILD_FIRMWARE    SIMULATOR IOS"
+	$(Q) make -j8 PLATFORM=simulator TARGET=ios clean
+	$(Q) make -j8 PLATFORM=simulator TARGET=ios IOS_PROVISIONNING_PROFILE="~/Downloads/NumWorks_Graphing_Calculator_Distribution.mobileprovision" output/release/simulator/ios/app/epsilon.official.ipa
+#TODO: which files are generated by codesign?
+#	$(Q) cp output/release/simulator/ios/app/epsilon.official.ipa output/stable_release/epsilon.ipa
+endif