diff --git a/src/common/baseplatform.ts b/src/common/baseplatform.ts
index e7af32e6..c3a6754d 100644
--- a/src/common/baseplatform.ts
+++ b/src/common/baseplatform.ts
@@ -431,6 +431,7 @@ export function getToolForFilename_6502(fn:string) : string {
   if (fn.endsWith(".dasm")) return "dasm";
   if (fn.endsWith(".acme")) return "acme";
   if (fn.endsWith(".wiz")) return "wiz";
+  if (fn.endsWith(".ecs")) return "ecs";
   return "dasm"; // .a
 }
 
diff --git a/src/common/ecs/compiler.ts b/src/common/ecs/compiler.ts
index ec6aa5fc..5b35a017 100644
--- a/src/common/ecs/compiler.ts
+++ b/src/common/ecs/compiler.ts
@@ -69,7 +69,7 @@ export class ECSCompiler extends Tokenizer {
 
     parseComponentField(): DataField {
         let name = this.expectIdent();
-        this.expectToken(':');
+        this.expectToken(':', 'I expected either a ":" or "end" here.'); // TODO
         let type = this.parseDataType();
         return { name: name.str, ...type };
     }
@@ -260,4 +260,10 @@ export class ECSCompiler extends Tokenizer {
             scope.dump(src);
         }
     }
+
+    export() {
+        let src = new SourceFileExport();
+        this.exportToFile(src);
+        return src.toString();
+    }
 }
diff --git a/src/platform/vcs.ts b/src/platform/vcs.ts
index cd42dbf2..9be588ab 100644
--- a/src/platform/vcs.ts
+++ b/src/platform/vcs.ts
@@ -60,6 +60,7 @@ function getToolForFilename_vcs(fn: string) {
   if (fn.endsWith(".wiz")) return "wiz";
   if (fn.endsWith(".bb") || fn.endsWith(".bas")) return "bataribasic";
   if (fn.endsWith(".ca65")) return "ca65";
+  if (fn.endsWith(".ecs")) return "ecs";
   return "dasm";
 }
 
diff --git a/src/worker/tools/ecs.ts b/src/worker/tools/ecs.ts
new file mode 100644
index 00000000..cfb01d80
--- /dev/null
+++ b/src/worker/tools/ecs.ts
@@ -0,0 +1,30 @@
+import { ECSCompiler } from "../../common/ecs/compiler";
+import { CompileError } from "../../common/tokenizer";
+import { CodeListingMap } from "../../common/workertypes";
+import { BuildStep, BuildStepResult, gatherFiles, getWorkFileAsString, putWorkFile, staleFiles } from "../workermain";
+
+export function assembleECS(step: BuildStep): BuildStepResult {
+    let compiler = new ECSCompiler();
+    gatherFiles(step, { mainFilePath: "main.ecs" });
+    var destpath = step.prefix + '.ca65';
+    if (staleFiles(step, [destpath])) {
+        let code = getWorkFileAsString(step.path);
+        try {
+            compiler.parseFile(code, step.path);
+        } catch (e) {
+            if (e instanceof CompileError) {
+                return { errors: compiler.errors };
+            } else {
+                throw e;
+            }
+        }
+        //var listings: CodeListingMap = {};
+        putWorkFile(destpath, compiler.export().toString());
+    }
+    return {
+        nexttool: "ca65",
+        path: destpath,
+        args: [destpath],
+        files: [destpath, 'vcs-ca65.h'], //TODO
+    };
+}
diff --git a/src/worker/workermain.ts b/src/worker/workermain.ts
index ffde5d72..be050701 100644
--- a/src/worker/workermain.ts
+++ b/src/worker/workermain.ts
@@ -1063,6 +1063,7 @@ import * as z80 from './tools/z80'
 import * as x86 from './tools/x86'
 import * as arm from './tools/arm'
 import * as script from './tools/script'
+import * as ecs from './tools/ecs'
 
 var TOOLS = {
   'dasm': dasm.assembleDASM,
@@ -1098,7 +1099,8 @@ var TOOLS = {
   'wiz': misc.compileWiz,
   'armips': arm.assembleARMIPS,
   'vasmarm': arm.assembleVASMARM,
-  'js': script.runJavascript,
+  //'js': script.runJavascript,
+  'ecs': ecs.assembleECS,
 }
 
 var TOOL_PRELOADFS = {
@@ -1125,6 +1127,7 @@ var TOOL_PRELOADFS = {
   'fastbasic': '65-atari8',
   'silice': 'Silice',
   'wiz': 'wiz',
+  'ecs': '65-none', // TODO: support multiple platforms
 }
 
 //const waitFor = delay => new Promise(resolve => setTimeout(resolve, delay)); // for testing