diff --git a/gulpfile.js b/gulpfile.js
index f8bbbca6b..39f161494 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -21,29 +21,39 @@ const releaseTasks = require('./scripts/gulpfiles/release_tasks');
 const cleanupTasks = require('./scripts/gulpfiles/cleanup_tasks');
 
 module.exports = {
+  // Default target if gulp invoked without specifying.
+  default: buildTasks.build,
+
+  // Main sequence targets.  They already invoke prerequisites.
+  cleanBuildDir: buildTasks.cleanBuildDir,
+  messages: buildTasks.messages,
+  tsc: buildTasks.tsc,
+  deps: buildTasks.deps,
+  minify: buildTasks.minify,
+  build: buildTasks.build,
+
+  // Manually-invokable targets that invoke prerequisites.
+  prepare: buildTasks.prepare,
+  format: buildTasks.format,
+  generate: buildTasks.generate,
+  clean: gulp.parallel(buildTasks.cleanBuildDir, packageTasks.cleanReleaseDir),
+  buildAdvancedCompilationTest: buildTasks.buildAdvancedCompilationTest,
+  
+  // Targets intended only for invocation by scripts; may omit prerequisites.
+  onlyBuildAdvancedCompilationTest: buildTasks.onlyBuildAdvancedCompilationTest,
+
+  // Legacy target, to be deleted.
+  checkin: buildTasks.checkin,
+
+  // TBD.
   deployDemos: appengineTasks.deployDemos,
   deployDemosBeta: appengineTasks.deployDemosBeta,
-  default: buildTasks.build,
-  generateLangfiles: buildTasks.generateLangfiles,
-  build: buildTasks.build,
-  buildDeps: buildTasks.deps,
-  buildLangfiles: buildTasks.langfiles,
-  buildCompiled: buildTasks.compiled,
-  buildAdvancedCompilationTest: buildTasks.advancedCompilationTest,
-  buildJavaScript: buildTasks.javaScript,
-  buildJavaScriptAndDeps: buildTasks.javaScriptAndDeps,
-  checkin: gulp.parallel(buildTasks.checkinBuilt),
-  checkinBuilt: buildTasks.checkinBuilt,
-  clangFormat: buildTasks.format,
-  clean: gulp.parallel(buildTasks.cleanBuildDir, packageTasks.cleanReleaseDir),
-  cleanBuildDir: buildTasks.cleanBuildDir,
   cleanReleaseDir: packageTasks.cleanReleaseDir,
   gitSyncDevelop: gitTasks.syncDevelop,
   gitSyncMaster: gitTasks.syncMaster,
   gitCreateRC: gitTasks.createRC,
   gitUpdateGithubPages: gitTasks.updateGithubPages,
   package: packageTasks.package,
-  prepare: buildTasks.prepare,
   checkLicenses: licenseTasks.checkLicenses,
   recompile: releaseTasks.recompile,
   prepareDemos: appengineTasks.prepareDemos,
diff --git a/package.json b/package.json
index 8a965a1f8..fca7b345a 100644
--- a/package.json
+++ b/package.json
@@ -32,15 +32,15 @@
     "clean:build": "gulp cleanBuildDir",
     "clean:release": "gulp cleanReleaseDir",
     "checkin": "gulp checkin",
-    "checkin:built": "gulp checkinBuilt",
     "deployDemos": "gulp deployDemos",
     "deployDemos:beta": "gulp deployDemosBeta",
-    "format": "gulp clangFormat",
+    "format": "gulp format",
     "format:sortrequires": "gulp sortRequires",
     "generate:langfiles": "gulp generateLangfiles",
     "license": "gulp checkLicenses",
     "lint": "eslint .",
     "lint:fix": "eslint . --fix",
+    "only:compile:advanced": "gulp onlyBuildAdvancedCompilationTest --debug",
     "package": "gulp package",
     "prepare": "gulp prepare",
     "prepareDemos": "gulp prepareDemos",
diff --git a/scripts/gulpfiles/build_tasks.js b/scripts/gulpfiles/build_tasks.js
index 8f0cecfeb..e764dd120 100644
--- a/scripts/gulpfiles/build_tasks.js
+++ b/scripts/gulpfiles/build_tasks.js
@@ -300,15 +300,12 @@ function prepare(done) {
     done();
     return;
   }
-  return buildJavaScriptAndDeps(done);
+  return exports.deps(done);
 }
 
-const buildJavaScriptAndDeps = gulp.series(buildJavaScript, buildDeps);
-
 /**
  * Builds Blockly as a JS program, by running tsc on all the files in
- * the core directory.  This must be run before buildDeps or
- * buildCompiled.
+ * the core directory.
  */
 function buildJavaScript(done) {
   execSync(
@@ -323,6 +320,8 @@ function buildJavaScript(done) {
  *
  * Also updates TEST_DEPS_FILE (deps.mocha.js), used by the mocha test
  * suite.
+ *
+ * Prerequisite: buildJavaScript.
  */
 function buildDeps(done) {
   const roots = [
@@ -639,6 +638,8 @@ function compile(options) {
  * blockly_compressed.js, blocks_compressed.js, etc.
  *
  * The deps.js file must be up-to-date.
+ *
+ * Prerequisite: buildDeps.
  */
 function buildCompiled() {
   // Get chunking.
@@ -673,6 +674,8 @@ function buildCompiled() {
 /**
  * This task builds Blockly core, blocks and generators together and uses
  * closure compiler's ADVANCED_COMPILATION mode.
+ *
+ * Prerequisite: buildDeps.
  */
 function buildAdvancedCompilationTest() {
   const srcs = [
@@ -701,26 +704,11 @@ function buildAdvancedCompilationTest() {
       .pipe(gulp.dest('./tests/compile/'));
 }
 
-/**
- * This task builds all of Blockly:
- *     blockly_compressed.js
- *     blocks_compressed.js
- *     javascript_compressed.js
- *     python_compressed.js
- *     php_compressed.js
- *     lua_compressed.js
- *     dart_compressed.js
- *     msg/json/*.js
- *     test/deps*.js
- */
-const build = gulp.parallel(
-    gulp.series(buildJavaScript, buildDeps, buildCompiled),
-    buildLangfiles,
-    );
-
 /**
  * This task copies built files from BUILD_DIR back to the repository
  * so they can be committed to git.
+ *
+ * Prerequisite: buildCompiled, buildLangfiles.
  */
 function checkinBuilt() {
   return gulp.src([
@@ -753,17 +741,23 @@ function format() {
       .pipe(gulp.dest('.'));
 }
 
-module.exports = {
-  prepare: prepare,
-  build: build,
-  javaScriptAndDeps: buildJavaScriptAndDeps,
-  javaScript: buildJavaScript,
-  deps: buildDeps,
-  generateLangfiles: generateLangfiles,
-  langfiles: buildLangfiles,
-  compiled: buildCompiled,
-  format: format,
-  checkinBuilt: checkinBuilt,
-  cleanBuildDir: cleanBuildDir,
-  advancedCompilationTest: buildAdvancedCompilationTest,
-}
+// Main sequence targets.  Each should invoke any immediate prerequisite(s).
+exports.cleanBuildDir = cleanBuildDir;
+exports.messages = buildLangfiles;
+exports.tsc = buildJavaScript;
+exports.deps = gulp.series(exports.tsc, buildDeps);
+exports.minify = gulp.series(exports.deps, buildCompiled);
+exports.build = gulp.parallel(exports.minify, exports.messages);
+
+// Manually-invokable targets, with prequisites where required.
+exports.prepare = prepare;
+exports.format = format;
+exports.generate = generateLangfiles;
+exports.buildAdvancedCompilationTest =
+    gulp.series(exports.deps, buildAdvancedCompilationTest);
+
+// Targets intended only for invocation by scripts; may omit prerequisites.
+exports.onlyBuildAdvancedCompilationTest = buildAdvancedCompilationTest;
+
+// Legacy target, to be deleted.
+exports.checkin = gulp.series(exports.build, checkinBuilt);
diff --git a/scripts/gulpfiles/git_tasks.js b/scripts/gulpfiles/git_tasks.js
index bfc28df4c..06268ee61 100644
--- a/scripts/gulpfiles/git_tasks.js
+++ b/scripts/gulpfiles/git_tasks.js
@@ -105,7 +105,7 @@ const updateGithubPages = gulp.series(
   },
   buildTasks.cleanBuildDir,
   buildTasks.build,
-  buildTasks.checkinBuilt,
+  buildTasks.checkin,
   function(done) {
     execSync('git commit -am "Rebuild"', { stdio: 'inherit' });
     execSync('git push ' + upstream_url + ' gh-pages --force', { stdio: 'inherit' });
diff --git a/scripts/gulpfiles/release_tasks.js b/scripts/gulpfiles/release_tasks.js
index 2841ad05e..7be0bd9fd 100644
--- a/scripts/gulpfiles/release_tasks.js
+++ b/scripts/gulpfiles/release_tasks.js
@@ -151,7 +151,7 @@ function updateBetaVersion(done) {
 const rebuildAll = gulp.series(
   buildTasks.cleanBuildDir,
   buildTasks.build,
-  buildTasks.checkinBuilt,
+  buildTasks.checkin,
   );
 
 // Package and publish to npm.
diff --git a/tests/run_all_tests.sh b/tests/run_all_tests.sh
index 36ae667b7..7823aa3fa 100755
--- a/tests/run_all_tests.sh
+++ b/tests/run_all_tests.sh
@@ -77,7 +77,7 @@ run_test_command "package" "npm run package"
 run_test_command "node" "./node_modules/.bin/mocha tests/node --config tests/node/.mocharc.js"
 
 # Attempt advanced compilation of a Blockly app.
-run_test_command "advanced_compile" "npm run test:compile:advanced"
+run_test_command "advanced_compile" "npm run only:compile:advanced"
 
 # End of tests.
 popd