diff --git a/Makefile b/Makefile
index c4086599..5afc70dc 100644
--- a/Makefile
+++ b/Makefile
@@ -1,23 +1,63 @@
+# Since we rely on paths relative to the makefile location, abort if make isn't being run from there.
+$(if $(findstring /,$(MAKEFILE_LIST)),$(error Please only invoke this makefile from the directory it resides in))
 
-.PHONY: verify-tag verify-changes release
+	# The files that need updating when incrementing the version number.
+VERSIONED_FILES := *.js *.json *.map README*
 
-default: release
 
-verify-tag:
+# Add the local npm packages' bin folder to the PATH, so that `make` can find them, when invoked directly.
+# Note that rather than using `$(npm bin)` the 'node_modules/.bin' path component is hard-coded, so that invocation works even from an environment
+# where npm is (temporarily) unavailable due to having deactivated an nvm instance loaded into the calling shell in order to avoid interference with tests.
+export PATH := $(shell printf '%s' "$$PWD/node_modules/.bin:$$PATH")
+UTILS := semver
+# Make sure that all required utilities can be located.
+UTIL_CHECK := $(or $(shell PATH="$(PATH)" which $(UTILS) >/dev/null && echo 'ok'),$(error Did you forget to run `npm install` after cloning the repo? At least one of the required supporting utilities not found: $(UTILS)))
+
+# Default target (by virtue of being the first non '.'-prefixed in the file).
+.PHONY: _no-target-specified
+_no-target-specified:
+	$(error Please specify the target to make - `make list` shows targets. Alternatively, use `npm test` to run the default tests; `npm run` shows all tests)
+
+# Lists all targets defined in this makefile.
+.PHONY: list
+list:
+	@$(MAKE) -pRrn : -f $(MAKEFILE_LIST) 2>/dev/null | awk -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' | command grep -v -e '^[^[:alnum:]]' -e '^$@$$command ' | sort
+
+# All-tests target: invokes the specified test suites for ALL shells defined in $(SHELLS).
+.PHONY: test
+test:
+	@npm test
+
+.PHONY: _ensure-tag
+_ensure-tag:
 ifndef TAG
-	$(error TAG is undefined)
+	$(error Please invoke with `make TAG=<new-version> release`, where <new-version> is either an increment specifier (patch, minor, major, prepatch, preminor, premajor, prerelease), or an explicit major.minor.patch version number)
 endif
 
-CHANGES_ERROR = $(error No CHANGES specified)
-
-verify-changes:
-	@ (git status -sb --porcelain | \grep -E '^( M|M ) CHANGES' > /dev/null) || (echo no CHANGES specified && exit 2)
+CHANGELOG_ERROR = $(error No CHANGES specified)
+.PHONY: _ensure-changelog
+_ensure-changelog:
+	@ (git status -sb --porcelain | command grep -E '^( M|[MA] ) CHANGES' > /dev/null) || (echo no CHANGES specified && exit 2)
 
-release: verify-changes verify-tag
-	@ OLD_TAG=`git describe --abbrev=0 --tags` && \
-		npm run minify && \
-		replace "$${OLD_TAG/v/}" "$(TAG)" -- *.min.js *.json README.md && \
-		replace "blob/master" "blob/v$(TAG)" -- *.min.js && \
-		git commit -m "v$(TAG)" *.js *.map *.json README.md CHANGES && \
-		git tag "v$(TAG)"
+# Ensures that the git workspace is clean.
+.PHONY: _ensure-clean
+_ensure-clean:
+	@[ -z "$$((git status --porcelain --untracked-files=no || echo err) | command grep -v 'CHANGES')" ] || { echo "Workspace is not clean; please commit changes first." >&2; exit 2; }
 
+# Makes a release; invoke with `make TAG=<versionOrIncrementSpec> release`.
+.PHONY: release
+release: _ensure-tag _ensure-changelog _ensure-clean
+	@old_ver=`git describe --abbrev=0 --tags --match 'v[0-9]*.[0-9]*.[0-9]*'` || { echo "Failed to determine current version." >&2; exit 1; }; old_ver=$${old_ver#v}; \
+	 new_ver=`echo "$(TAG)" | sed 's/^v//'`; new_ver=$${new_ver:-patch}; \
+	 if printf "$$new_ver" | command grep -q '^[0-9]'; then \
+	   semver "$$new_ver" >/dev/null || { echo 'Invalid version number specified: $(TAG) - must be major.minor.patch' >&2; exit 2; }; \
+	   semver -r "> $$old_ver" "$$new_ver" >/dev/null || { echo 'Invalid version number specified: $(TAG) - must be HIGHER than current one.' >&2; exit 2; } \
+	 else \
+	   new_ver=`semver -i "$$new_ver" "$$old_ver"` || { echo 'Invalid version-increment specifier: $(TAG)' >&2; exit 2; } \
+	 fi; \
+	 printf "=== Bumping version **$$old_ver** to **$$new_ver** before committing and tagging:\n=== TYPE 'proceed' TO PROCEED, anything else to abort: " && read response && [ "$$response" = 'proceed' ] || { echo 'Aborted.' >&2; exit 2; };  \
+     npm run minify; \
+     replace "$$old_ver" "$$new_ver" -- $(VERSIONED_FILES) && \
+     replace "blob/master" "blob/v$$new_ver" -- *.min.js && \
+	 git commit -m "v$$new_ver" $(VERSIONED_FILES) CHANGES && \
+	 git tag -a -m "v$$new_ver" "v$$new_ver"
diff --git a/package.json b/package.json
index 23897892..39e2fb94 100644
--- a/package.json
+++ b/package.json
@@ -40,7 +40,9 @@
     "eslint": "^0.18.0",
     "jasmine-node": "^1.14.5",
     "jscs": "^1.11.3",
-    "uglify-js": "=2.4.17"
+    "uglify-js": "=2.4.17",
+    "replace": "^0.3.0",
+    "semver": "^4.3.3"
   },
   "engines": {
     "node": ">=0.4.0"