diff --git a/src/components/EditorPanel.tsx b/src/components/EditorPanel.tsx
index 2fc8daa..8a85e76 100644
--- a/src/components/EditorPanel.tsx
+++ b/src/components/EditorPanel.tsx
@@ -6,14 +6,12 @@ import openscadEditorOptions from '../language/openscad-editor-options';
 import * as monaco from 'monaco-editor/esm/vs/editor/editor.api';
 import { Button } from 'primereact/button';
 import { MenuItem } from 'primereact/menuitem';
-import { TreeSelect } from 'primereact/treeselect';
-import TreeNode from 'primereact/treenode';
 import { Menu } from 'primereact/menu';
-import { getParentDir, librariesFolder } from '../fs/filesystem';
 import { buildUrlForStateParams } from '../state/fragment-state';
 import { blankProjectState } from '../state/initial-state';
 import { ModelContext, FSContext } from './contexts';
-import FilePicker, { isFileWritable } from './FilePicker';
+import FilePicker, {  } from './FilePicker';
+import { isFileWritable } from '../state/model';
 
 // import "primereact/resources/themes/lara-light-indigo/theme.css";
 // import "primereact/resources/primereact.min.css";
@@ -22,46 +20,6 @@ import FilePicker, { isFileWritable } from './FilePicker';
 let monacoInstance: Monaco
 loader.init().then(mi => monacoInstance = mi);
 
-// const isFileWritable = (path: string) => getParentDir(path) === '/home'
-
-// function listFilesAsNodes(fs: FS, path: string): TreeNode[] {
-//   const files: [string, string][] = []
-//   const dirs: [string, string][] = []
-//   for (const name of fs.readdirSync(path)) {
-//     if (name.startsWith('.')) {
-//       continue;
-//     }
-//     const childPath = `${path}/${name}`;
-//     const stat = fs.lstatSync(childPath);
-//     const isDirectory = stat.isDirectory();
-//     if (!isDirectory && !name.endsWith('.scad')) {
-//       continue;
-//     }
-//     (isDirectory ? dirs : files).push([name, childPath]);
-//   }
-//   [files, dirs].forEach(arr => arr.sort(([a], [b]) => a.localeCompare(b)));
-
-//   const nodes: TreeNode[] = []
-//   for (const [arr, isDirectory] of [[files, false], [dirs, true]] as [[string, string][], boolean][]) {
-//     for (const [name, path] of arr) {
-//       const children = isDirectory ? listFilesAsNodes(fs, path) : undefined;
-//       if (isDirectory && children!.length == 0) {
-//         continue;
-//       }
-//       nodes.push({
-//         // icon: path == '/home' ? 'pi-home' : ...
-//         icon: isDirectory ? 'pi pi-folder' : isFileWritable(path) ? 'pi pi-file' : 'pi pi-lock',
-//         label: name,
-//         data: path,
-//         key: path,
-//         children,
-//         selectable: !isDirectory // && (name == 'LICENSE' || name.endsWith('.scad') || name.endsWith('.scad')
-//       });
-//     }
-//   }
-//   return nodes;
-// }
-
 export default function EditorPanel({className, style}: {className?: string, style?: CSSProperties}) {
 
   const model = useContext(ModelContext);
@@ -71,9 +29,7 @@ export default function EditorPanel({className, style}: {className?: string, sty
 
   const state = model.state;
 
-  // const fs = useContext(FSContext);
   const [editor, setEditor] = useState(null as monaco.editor.IStandaloneCodeEditor | null)
-  // const [modelFile, setModelFile] = useState(state.params.sourcePath);
 
   if (editor) {
     const checkerRun = state.lastCheckerRun;
diff --git a/src/components/FilePicker.tsx b/src/components/FilePicker.tsx
index 25521cc..6fd99bd 100644
--- a/src/components/FilePicker.tsx
+++ b/src/components/FilePicker.tsx
@@ -3,12 +3,8 @@
 import { CSSProperties, useContext } from 'react';
 import { TreeSelect } from 'primereact/treeselect';
 import TreeNode from 'primereact/treenode';
-import { getParentDir, librariesFolder } from '../fs/filesystem';
 import { ModelContext, FSContext } from './contexts';
-
-export const isFileWritable = (path: string) => getParentDir(path) === '/home'
-
-// export const isFileWritable = (path: string) => !path.startsWith(librariesFolder + '/');
+import { isFileWritable } from '../state/model';
 
 function listFilesAsNodes(fs: FS, path: string, accept?: (path: string) => boolean): TreeNode[] {
   const files: [string, string][] = []
@@ -58,23 +54,7 @@ export default function FilePicker({className, style}: {className?: string, styl
 
   const fs = useContext(FSContext);
 
-  const fsItems = fs && [
-    {
-      icon: 'pi pi-home',
-      label: 'User files',
-      key: '/home',
-      children: listFilesAsNodes(fs, '/home'),//
-      // children: listFilesAsNodes(fs, '/', f => f != librariesFolder && !f.startsWith(`${librariesFolder}/`)),
-      selectable: false
-    },
-    {
-      icon: 'pi pi-database',
-      label: 'Builtin libraries',
-      key: librariesFolder,
-      children: listFilesAsNodes(fs, librariesFolder),
-      selectable: false
-    },
-  ] || [];
+  const fsItems = fs && listFilesAsNodes(fs, '/home')
 
   return (
       <TreeSelect 
diff --git a/src/components/Footer.tsx b/src/components/Footer.tsx
index 877665f..0fad6a5 100644
--- a/src/components/Footer.tsx
+++ b/src/components/Footer.tsx
@@ -94,24 +94,32 @@ export default function Footer({style}: {style?: CSSProperties}) {
         title="Render the model (F6 / Ctrl+Enter). Models can test $preview to enable more detail in renders only."
         label="Render" />
       
-      {/* {state.error != null &&
-        <i className="pi pi-exclamation-circle" style={{color: 'red'}} title={state.error}></i>} */}
+      {(state.lastCheckerRun || state.output) &&
+        <Button type="button"
+            // label={state.view.logs ? "Hide logs" : "Show logs"}
+            label="Logs"
+            icon="pi pi-align-left"
+            text={!state.view.logs}
+            onClick={() => model.logsVisible = !state.view.logs}
+            // onLabel="Logs" offLabel="Logs" 
+            // onIcon="pi pi-align-left"
+            // offIcon="pi pi-align-left"
+            className={maxMarkerSeverity && `p-button-${severityByMarkerSeverity.get(maxMarkerSeverity) ?? 'success'}`}
+            >
+          {getBadge(monaco.MarkerSeverity.Error)}
+          {getBadge(monaco.MarkerSeverity.Warning)}
+          {getBadge(monaco.MarkerSeverity.Info)}
+        </Button>}
 
-      <Button type="button"
-          // label={state.view.logs ? "Hide logs" : "Show logs"}
-          label="Logs"
-          icon="pi pi-align-left"
-          text={!state.view.logs}
-          onClick={() => model.logsVisible = !state.view.logs}
-          // onLabel="Logs" offLabel="Logs" 
-          // onIcon="pi pi-align-left"
-          // offIcon="pi pi-align-left"
-          className={maxMarkerSeverity && `p-button-${severityByMarkerSeverity.get(maxMarkerSeverity) ?? 'success'}`}
-          >
-        {getBadge(monaco.MarkerSeverity.Error)}
-        {getBadge(monaco.MarkerSeverity.Warning)}
-        {getBadge(monaco.MarkerSeverity.Info)}
-      </Button>
+      {state.output && (
+        <Button icon='pi pi-download'
+          title={`Download ${state.output.isPreview ? "preview.stl" : "render.stl"} (${state.output.formattedStlFileSize})`}
+          severity="secondary"
+          text
+          // label={state.output.isPreview ? "preview.stl" : "render.stl"}
+          iconPos='right'
+          onClick={() => downloadOutput(state)} />
+      )}
 
       {/* {state.output &&
         <span style={{color: 'blue'}}>
@@ -130,24 +138,6 @@ export default function Footer({style}: {style?: CSSProperties}) {
       <ConfirmDialog />
 
       <Toast ref={toast} />
-
-      {state.output && (
-        <Button icon='pi pi-download'
-          title={`Download ${state.output.isPreview ? "preview.stl" : "render.stl"} (${state.output.formattedStlFileSize})`}
-          severity="secondary"
-          text
-          // label={state.output.isPreview ? "preview.stl" : "render.stl"}
-          iconPos='right'
-          onClick={() => downloadOutput(state)} />
-        // <a href={state.output.stlFileURL}
-        // target="_blank" 
-        // download={state.output.isPreview ? "preview.stl" : "render.stl"}
-        // title="STL Download">
-        //     {state.output.isPreview ? "preview.stl" : "render.stl"} ({state.output.formattedStlFileSize})
-        // </a>
-      )}
-
-      <SettingsMenu />
       
       <HelpMenu />
     </div>
diff --git a/src/components/PanelSwitcher.tsx b/src/components/PanelSwitcher.tsx
index 64e8498..77d0008 100644
--- a/src/components/PanelSwitcher.tsx
+++ b/src/components/PanelSwitcher.tsx
@@ -5,6 +5,7 @@ import { SingleLayoutComponentId } from '../state/app-state'
 import { TabMenu } from 'primereact/tabmenu';
 import { ToggleButton } from 'primereact/togglebutton';
 import { ModelContext, FSContext } from './contexts';
+import SettingsMenu from './SettingsMenu';
 
 export default function PanelSwitcher() {
   const model = useContext(ModelContext);
@@ -49,15 +50,18 @@ export default function PanelSwitcher() {
                     />
                   )}
               </div>
-          :   <TabMenu
+          :   <>
+                <TabMenu
                   activeIndex={singleTargets.map(t => t.id).indexOf(state.view.layout.focus)}
                   style={{
                     flex: 1,
                     // justifyContent: 'center'
                   }}
                   model={singleTargets.map(({icon, label, id}) => 
-                      ({icon, label, disabled: id === 'customizer', command: () => model.changeSingleVisibility(id)}))} />
+                  ({icon, label, disabled: id === 'customizer', command: () => model.changeSingleVisibility(id)}))} />
+              </>
         }
+        <SettingsMenu />
       </div>
     </div>
   );
diff --git a/src/fs/filesystem.ts b/src/fs/filesystem.ts
index 3344e7a..d3a03b1 100644
--- a/src/fs/filesystem.ts
+++ b/src/fs/filesystem.ts
@@ -2,8 +2,6 @@
 
 import { zipArchives } from "./zip-archives";
 
-export const librariesFolder = '/libraries'
-
 declare var BrowserFS: BrowserFSInterface
 
 export type FSMounts = {
@@ -13,6 +11,7 @@ export type FSMounts = {
 export type Symlinks = {[alias: string]: string};
 
 export const getParentDir = (path: string) => path.split('/').slice(0, -1).join('/');
+export const getFileName = (path: string) => path.split('/').splice(-1)[0];
 
 export function readDirAsArray(fs: FS, path: string): Promise<string[] | undefined> {
   return new Promise((res, rej) => fs.readdir(path, (err, files) => err ? rej(err) : res(files)));
@@ -74,12 +73,12 @@ function configureAndInstallFS(windowOrSelf: Window, options: any) {
   });
 }
 
-export async function createEditorFS(workingDir='/home'): Promise<FS> {
+export async function createEditorFS(prefix: string): Promise<FS> {
   const archiveNames = Object.keys(zipArchives);
   const librariesMounts = await getBrowserFSLibrariesMounts(archiveNames);
   const allMounts: FSMounts = {};
   for (const n in librariesMounts) {
-    allMounts[`${workingDir}/${n}`] = librariesMounts[n];
+    allMounts[`${prefix}${n}`] = librariesMounts[n];
   }
 
   await configureAndInstallFS(typeof window === 'object' && window || self, {
diff --git a/src/runner/actions.ts b/src/runner/actions.ts
index a7a72f8..f35ab64 100644
--- a/src/runner/actions.ts
+++ b/src/runner/actions.ts
@@ -26,8 +26,8 @@ export const checkSyntax =
           const result = await job;
           // console.log(result);
           res(processMergedOutputs(result.mergedOutputs, {shiftSourceLines: {
-            [sourcePath]: 1,
-            [sourcePath.split('/').slice(-1)[0]]: 1
+            sourcePath,
+            skipLines: 1,
           }}));
         } catch (e) {
           console.error(e);
@@ -52,7 +52,7 @@ export const render =
  turnIntoDelayableExecution(renderDelay, (params: RenderArgs) => {
     const args = [
       params.sourcePath,
-      "-o", "/home/out.stl",
+      "-o", "out.stl",
       "--export-format=binstl",
       ...(params.features ?? []).map(f => `--enable=${f}`),
       ...(params.extraArgs ?? [])
@@ -68,7 +68,7 @@ export const render =
       // wasmMemory,
       inputs: [[params.sourcePath, source]],
       args,
-      outputPaths: ['/home/out.stl']
+      outputPaths: ['out.stl']
     });
 
     return AbortablePromise<RenderOutput>((resolve, reject) => {
@@ -79,8 +79,8 @@ export const render =
 
           const {logText, markers} = processMergedOutputs(result.mergedOutputs, {
             shiftSourceLines: {
-              [params.sourcePath]: prefixLines.length,
-              [params.sourcePath.split('/').slice(-1)[0]]: prefixLines.length
+              sourcePath: params.sourcePath,
+              skipLines: prefixLines.length
             }
           });
     
diff --git a/src/runner/openscad-worker.ts b/src/runner/openscad-worker.ts
index 0f704e7..d53d7da 100644
--- a/src/runner/openscad-worker.ts
+++ b/src/runner/openscad-worker.ts
@@ -2,7 +2,7 @@
 
 import OpenSCAD from "../wasm/openscad.js";
 
-import { createEditorFS, getBrowserFSLibrariesMounts, librariesFolder, symlinkLibraries } from "../fs/filesystem";
+import { createEditorFS, getBrowserFSLibrariesMounts, symlinkLibraries } from "../fs/filesystem";
 import { OpenSCADInvocation, OpenSCADInvocationResults } from "./openscad-runner";
 import { zipArchives } from "../fs/zip-archives";
 declare var BrowserFS: BrowserFSInterface
@@ -17,7 +17,7 @@ export type MergedOutputs = {stdout?: string, stderr?: string, error?: string}[]
 
 addEventListener('message', async (e) => {
 
-  const { inputs, args, outputPaths, wasmMemory, workingDir } = e.data as OpenSCADInvocation;
+  const { inputs, args, outputPaths, wasmMemory } = e.data as OpenSCADInvocation;
 
   const mergedOutputs: MergedOutputs = [];
   try {
diff --git a/src/runner/output-parser.ts b/src/runner/output-parser.ts
index a9ff510..494e91d 100644
--- a/src/runner/output-parser.ts
+++ b/src/runner/output-parser.ts
@@ -1,4 +1,5 @@
 import * as monaco from 'monaco-editor/esm/vs/editor/editor.api';
+import { getFileName } from '../fs/filesystem';
 import { MergedOutputs } from "./openscad-worker";
 
 const ignoredLogs = new Set([
@@ -6,7 +7,10 @@ const ignoredLogs = new Set([
 ]);
 
 type MergedOutputsOptions = {
-  shiftSourceLines: {[path: string]: number}
+  shiftSourceLines?: {
+    sourcePath: string,
+    skipLines: number,
+  }
 }
 export const processMergedOutputs = (outputs: MergedOutputs, opts: MergedOutputsOptions) => ({
   logText: joinMergedOutputs(outputs, opts),
@@ -41,9 +45,14 @@ export function parseMergedOutputs(mergedOutputs: MergedOutputs, opts: MergedOut
       severity: monaco.MarkerSeverity.Error
     })
   }
+  const shiftSourceName = opts.shiftSourceLines && getFileName(opts.shiftSourceLines.sourcePath);
   const getLine = (path: string, lineStr: string) => {
-    const shift = opts.shiftSourceLines[path] ?? 0;
-    return Number(lineStr) - shift;
+    const line = Number(lineStr);
+    if (shiftSourceName && getFileName(path) == shiftSourceName) {
+      return line - opts.shiftSourceLines!.skipLines;
+    } else {
+      return line;
+    }
   }
   for (const {stderr, stdout, error} of mergedOutputs){
     if (stderr) {
diff --git a/src/state/initial-state.ts b/src/state/initial-state.ts
index 155568c..d69f36d 100644
--- a/src/state/initial-state.ts
+++ b/src/state/initial-state.ts
@@ -3,7 +3,7 @@
 import defaultScad from './default-scad';
 import { State } from './app-state';
 
-export const defaultSourcePath = '/home/playground.scad';
+export const defaultSourcePath = 'playground.scad';
   
 export const blankProjectState: State = {
   params: {
diff --git a/src/state/model.ts b/src/state/model.ts
index 4e29c1a..dfec22e 100644
--- a/src/state/model.ts
+++ b/src/state/model.ts
@@ -5,6 +5,11 @@ import { MultiLayoutComponentId, SingleLayoutComponentId, State } from "./app-st
 import { bubbleUpDeepMutations } from "./deep-mutate";
 import { writeStateInFragment } from "./fragment-state";
 import { formatBytes, formatMillis } from '../utils'
+import { getParentDir } from "../fs/filesystem";
+
+// export const isFileWritable = (path: string) => !path.startsWith('/');
+export const isFileWritable = (path: string) => getParentDir(path) === '/home';
+// export const isFileWritable = (path: string) => !path.startsWith(librariesFolder + '/');
 
 export class Model {
   constructor(private fs: FS, public state: State, private setStateCallback?: (state: State) => void) {
@@ -105,7 +110,10 @@ export class Model {
 
   private processSource() {
     const params = this.state.params;
-    // this.fs.writeFile(params.sourcePath, params.source);
+    if (isFileWritable(params.sourcePath)) {
+      const absolutePath = `/home/${params.sourcePath}`;
+      this.fs.writeFile(absolutePath, params.source);
+    }
     this.checkSyntax();
     this.render({isPreview: true, now: false});
   }