diff --git a/Makefile b/Makefile
index 806af32..03429fb 100644
--- a/Makefile
+++ b/Makefile
@@ -22,6 +22,7 @@ OBJCOPY   := avr-objcopy
 AVD       := avrdude
 MKDIR     := mkdir -p
 RMR       := rm -rf
+GIT       := git
 
 SRCDIR    := src
 BINDIR    := bin
@@ -79,19 +80,24 @@ distclean: clean
 	$(Q) $(RMR) $(BINDIR)
 
 .PHONY: listen
-listen: ./opt/tools/serial-listen.py
-	$(E) "[PY3] $<"
+listen: opt/tools/serial-listen
+	$(E) "[RUN] $<"
 	$(Q) ./$<
 
 .PHONY: webgui
-webgui: ./opt/webgui/Makefile
-	$(E) "[MAK] $(<D)"
+webgui: opt/webgui/Makefile
+	$(E) "[MAK] $<"
 	$(Q) $(MAKE) -sC $(<D)
 
 $(TMPDIRS):
 	$(E) "[DIR] $@"
 	$(Q) $(MKDIR) $@
 
+# Initialize optional git submodules if needed
+opt/tools/serial-listen opt/webgui/Makefile:
+	$(E) "[GIT] Initializing submodules..."
+	$(Q) $(GIT) submodule update --init
+
 # ==============================================================================
 # PRIMARY BUILD TARGET AND PATTERN RULES
 # ==============================================================================
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 4d80dd7..3875f5b 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -1,6 +1,8 @@
 ## Changelog
 
 ### v0.75-alpha1
+- Auto-initialize optional submodules when needed.
+- Reduce number of watchdog timer resets.
 - Fix parser tail pointer semantics.
 - Improve sensor log readability and minor naming fixes.
 - Add multiple README sections and use markdown formatting.
diff --git a/docs/README.md b/docs/README.md
index 4ab34ed..36437df 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -27,19 +27,18 @@ build and install the project:
 
 If there are any errors during the flashing process you
 should find more information in `bin/core.log`. See the
-Makefile for all build-related settings and make sure
-they are correct for your current build environment.
+Makefile for all build settings and make sure they are
+correct for your current environment.
 
-To remove build related auxiliary files you may use one
+To remove build-related auxiliary files you may use one
 of these commands:
 
     make clean
     make distclean
 
 You can listen on the serial debug interface by running
-the command below (if you have initialized the optional
-submodules as described in the section 'Setting a New
-Target'):
+the command below. This will also initialize all optional
+submodules on first invocation.
 
     make listen
 
@@ -52,11 +51,12 @@ information on how to configure the server.
 
 ### Setting a New Target
 
-The script below allows you to send serial commands (you
-may need to run `git submodule update --init` first, if
-the `opt/tools/` directory is empty):
+The script below allows you to send serial commands. You
+may need to run `git submodule update --init` first if the
+`opt/tools/` directory is empty (but this should usually be
+done automatically when needed by another Makefile rule).
 
-    opt/tools/serial-send.py <command> <args ...>
+    opt/tools/serial-send <command> <args ...>
 
 Issue the SET command to update the target settings:
 
diff --git a/opt/tools b/opt/tools
index 565c8b7..56c8135 160000
--- a/opt/tools
+++ b/opt/tools
@@ -1 +1 @@
-Subproject commit 565c8b74569b900b3de35cc5ecf16d4789525881
+Subproject commit 56c81351722e21695067790e6aeb09f78c8e4037
diff --git a/opt/webgui b/opt/webgui
index bd60c0e..d9f6de6 160000
--- a/opt/webgui
+++ b/opt/webgui
@@ -1 +1 @@
-Subproject commit bd60c0e13dce8210262fa0899f640b0a022b5085
+Subproject commit d9f6de6bd9f2e2ede6f8e0eac5ec951d90332894