diff --git a/packages/java/src/browser/java-resource.ts b/packages/java/src/browser/java-resource.ts
index 202f4448f9ab9..9f2dde3d5e3c4 100644
--- a/packages/java/src/browser/java-resource.ts
+++ b/packages/java/src/browser/java-resource.ts
@@ -43,7 +43,7 @@ export class JavaResourceResolver implements ResourceResolver {
 
     resolve(uri: URI): JavaResource {
         if (uri.scheme !== JAVA_SCHEME) {
-            throw new Error("The given uri is not a java uri: " + uri);
+            throw new Error("The given URI is not a valid Java uri: " + uri);
         }
         return new JavaResource(uri, this.clientContribution);
     }
diff --git a/packages/java/src/node/java-contribution.ts b/packages/java/src/node/java-contribution.ts
index 9b85b2ef54693..ffbf41b39a9d2 100644
--- a/packages/java/src/node/java-contribution.ts
+++ b/packages/java/src/node/java-contribution.ts
@@ -29,7 +29,7 @@ export class JavaContribution extends BaseLanguageServerContribution {
         const serverPath = path.resolve(__dirname, 'server');
         const jarPaths = glob.sync('**/plugins/org.eclipse.equinox.launcher_*.jar', { cwd: serverPath });
         if (jarPaths.length === 0) {
-            throw new Error('The java server launcher is not found.');
+            throw new Error('The Java server launcher is not found.');
         }
 
         const jarPath = path.resolve(serverPath, jarPaths[0]);
@@ -55,7 +55,7 @@ export class JavaContribution extends BaseLanguageServerContribution {
             '-jar', jarPath,
             '-configuration', configurationPath,
             '-data', workspacePath
-        )
+        );
 
         Promise.all([
             this.startSocketServer(), this.startSocketServer()
@@ -70,9 +70,8 @@ export class JavaContribution extends BaseLanguageServerContribution {
             env.STDIN_PORT = inServer.address().port;
             env.STDOUT_HOST = outServer.address().address;
             env.STDOUT_PORT = outServer.address().port;
-            this.createProcessSocketConnection(inSocket, outSocket, command, args, {
-                env: env
-            }).then(serverConnection => this.forward(clientConnection, serverConnection));
+            this.createProcessSocketConnection(inSocket, outSocket, command, args, { env })
+                .then(serverConnection => this.forward(clientConnection, serverConnection));
         });
     }
 }
diff --git a/packages/languages/package.json b/packages/languages/package.json
index 4375fc3baeca0..1ae43feb44a8f 100644
--- a/packages/languages/package.json
+++ b/packages/languages/package.json
@@ -4,6 +4,7 @@
   "description": "Theia - Languages Extension",
   "dependencies": {
     "@theia/core": "^0.2.1",
+    "@theia/process": "^0.2.1",
     "vscode-base-languageclient": "^0.0.1-alpha.3",
     "vscode-languageserver": "^3.4.0"
   },
@@ -46,4 +47,4 @@
   "nyc": {
     "extends": "../../configs/nyc.json"
   }
-}
+}
\ No newline at end of file
diff --git a/packages/languages/src/node/language-server-contribution.ts b/packages/languages/src/node/language-server-contribution.ts
index 57cd612995301..34f1d15902893 100644
--- a/packages/languages/src/node/language-server-contribution.ts
+++ b/packages/languages/src/node/language-server-contribution.ts
@@ -7,21 +7,22 @@
 
 import * as net from 'net';
 import * as cp from 'child_process';
-import { injectable } from "inversify";
+import { injectable, inject } from "inversify";
 import { Message, isRequestMessage } from 'vscode-ws-jsonrpc';
 import { InitializeParams, InitializeRequest } from 'vscode-languageserver-protocol';
 import {
     createProcessSocketConnection,
-    createProcessStreamConnection,
+    createStreamConnection,
     forward,
     IConnection
 } from 'vscode-ws-jsonrpc/lib/server';
 import { MaybePromise } from "@theia/core/lib/common";
 import { LanguageContribution } from "../common";
+import { RawProcess, RawProcessFactory } from '@theia/process/lib/node/raw-process';
 
 export {
     LanguageContribution, IConnection, Message
-}
+};
 
 export const LanguageServerContribution = Symbol('LanguageServerContribution');
 export interface LanguageServerContribution extends LanguageContribution {
@@ -30,10 +31,14 @@ export interface LanguageServerContribution extends LanguageContribution {
 
 @injectable()
 export abstract class BaseLanguageServerContribution implements LanguageServerContribution {
+
     abstract readonly id: string;
     abstract readonly name: string;
     abstract start(clientConnection: IConnection): void;
 
+    @inject(RawProcessFactory)
+    protected readonly processFactory: RawProcessFactory;
+
     protected forward(clientConnection: IConnection, serverConnection: IConnection): void {
         forward(clientConnection, serverConnection, this.map.bind(this));
     }
@@ -48,36 +53,34 @@ export abstract class BaseLanguageServerContribution implements LanguageServerCo
         return message;
     }
 
-    protected createProcessSocketConnection(
-        outSocket: MaybePromise<net.Socket>, inSocket: MaybePromise<net.Socket>,
-        command: string, args?: string[], options?: cp.SpawnOptions
-    ): Promise<IConnection> {
+    protected async createProcessSocketConnection(outSocket: MaybePromise<net.Socket>, inSocket: MaybePromise<net.Socket>,
+        command: string, args?: string[], options?: cp.SpawnOptions): Promise<IConnection> {
+
         const process = this.spawnProcess(command, args, options);
-        return Promise.all([
-            Promise.resolve(outSocket),
-            Promise.resolve(inSocket)
-        ]).then(result => createProcessSocketConnection(process, result[0], result[1]));
+        const [outSock, inSock] = await Promise.all([outSocket, inSocket]);
+        return createProcessSocketConnection(process.process, outSock, inSock);
     }
 
     protected createProcessStreamConnection(command: string, args?: string[], options?: cp.SpawnOptions): IConnection {
         const process = this.spawnProcess(command, args, options);
-        return createProcessStreamConnection(process);
+        return createStreamConnection(process.output, process.input, () => process.kill());
     }
 
-    protected spawnProcess(command: string, args?: string[], options?: cp.SpawnOptions): cp.ChildProcess {
-        const serverProcess = cp.spawn(command, args, options);
-        serverProcess.once('error', this.onDidFailSpawnProcess.bind(this));
-        serverProcess.stderr.on('data', this.logError.bind(this));
-        return serverProcess;
+    protected spawnProcess(command: string, args?: string[], options?: cp.SpawnOptions): RawProcess {
+        const rawProcess = this.processFactory({ command, args, options });
+        const { process } = rawProcess;
+        process.once('error', this.onDidFailSpawnProcess.bind(this));
+        process.stderr.on('data', this.logError.bind(this));
+        return rawProcess;
     }
 
     protected onDidFailSpawnProcess(error: Error): void {
-        console.error(error)
+        console.error(error);
     }
 
     protected logError(data: string | Buffer) {
         if (data) {
-            console.error(`${this.name}: ${data}`)
+            console.error(`${this.name}: ${data}`);
         }
     }
 
@@ -89,7 +92,7 @@ export abstract class BaseLanguageServerContribution implements LanguageServerCo
 
     protected startSocketServer(): Promise<net.Server> {
         return new Promise(resolve => {
-            const server = net.createServer()
+            const server = net.createServer();
             server.addListener('listening', () =>
                 resolve(server)
             );
diff --git a/packages/process/src/node/process-manager.ts b/packages/process/src/node/process-manager.ts
index 21ba03d122d72..6d8b16d571c0d 100644
--- a/packages/process/src/node/process-manager.ts
+++ b/packages/process/src/node/process-manager.ts
@@ -4,22 +4,26 @@
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
-import { injectable } from 'inversify';
+import { injectable, inject } from 'inversify';
 import { Process } from './process';
 import { Emitter, Event } from '@theia/core/lib/common';
+import { ILogger } from '@theia/core/lib/common/logger';
 
 @injectable()
 export class ProcessManager {
 
-    protected readonly processes: Map<number, Process> = new Map();
     protected id: number = 0;
-    protected readonly deleteEmitter = new Emitter<number>();
+    protected readonly processes: Map<number, Process>;
+    protected readonly deleteEmitter: Emitter<number>;
+
+    constructor( @inject(ILogger) protected logger: ILogger) {
+        this.processes = new Map();
+        this.deleteEmitter = new Emitter<number>();
+    }
 
     register(process: Process): number {
-        const id = this.id;
-        this.processes.set(id, process);
-        this.id++;
-        return id;
+        this.processes.set(++this.id, process);
+        return this.id;
     }
 
     get(id: number): Process | undefined {
@@ -28,11 +32,14 @@ export class ProcessManager {
 
     delete(process: Process): void {
         process.kill();
-        this.processes.delete(process.id);
+        if (!this.processes.delete(process.id)) {
+            this.logger.warn(`The process was not registered via this manager. Anyway, we kill your process. PID: ${process.pid}.`);
+        }
         this.deleteEmitter.fire(process.id);
     }
 
     get onDelete(): Event<number> {
         return this.deleteEmitter.event;
     }
+
 }
diff --git a/packages/process/src/node/process.ts b/packages/process/src/node/process.ts
index 946a45420b67e..4ed5108c0ce03 100644
--- a/packages/process/src/node/process.ts
+++ b/packages/process/src/node/process.ts
@@ -6,7 +6,7 @@
  */
 
 import * as stream from 'stream';
-import { injectable, inject, unmanaged } from "inversify";
+import { injectable, inject } from "inversify";
 import { ProcessManager } from './process-manager';
 import { ILogger, Emitter, Event } from '@theia/core/lib/common';
 
@@ -27,6 +27,7 @@ export abstract class Process {
     readonly exitEmitter: Emitter<IProcessExitEvent>;
     readonly errorEmitter: Emitter<Error>;
     abstract readonly pid: number;
+    abstract readonly input: stream.Writable;
     abstract readonly output: stream.Readable;
     protected _killed = false;
 
diff --git a/packages/process/src/node/raw-process.ts b/packages/process/src/node/raw-process.ts
index 52d7084ede17f..9edb071ae1b28 100644
--- a/packages/process/src/node/raw-process.ts
+++ b/packages/process/src/node/raw-process.ts
@@ -27,9 +27,11 @@ export interface RawProcessFactory {
 @injectable()
 export class RawProcess extends Process {
 
+    readonly input: stream.Writable;
     readonly output: stream.Readable;
     readonly errorOutput: stream.Readable;
-    protected process: child.ChildProcess;
+    // XXX: Do we have to make this public? How to attach additional listeners to the underlying process then?
+    readonly process: child.ChildProcess;
 
     constructor(
         @inject(RawProcessOptions) options: RawProcessOptions,
@@ -50,6 +52,7 @@ export class RawProcess extends Process {
         this.process.on('exit', this.emitOnExit.bind(this));
 
         this.output = this.process.stdout;
+        this.input = this.process.stdin;
         this.errorOutput = this.process.stderr;
     }
 
diff --git a/packages/process/src/node/terminal-process.ts b/packages/process/src/node/terminal-process.ts
index d2d4040bc8c20..04e52e96c06ef 100644
--- a/packages/process/src/node/terminal-process.ts
+++ b/packages/process/src/node/terminal-process.ts
@@ -24,22 +24,37 @@ export const TerminalProcessFactory = Symbol("TerminalProcessFactory");
 export type TerminalProcessFactory = (options: TerminalProcessOptions) => TerminalProcess;
 
 /* Use this instead of the node-pty stream, since the node-pty stream is already resumed.  */
-export class TerminalReadableStream extends stream.Readable {
-    constructor(protected readonly terminal: any, opts?: any) {
+class TerminalReadableStream extends stream.Readable {
+
+    constructor(protected readonly terminal: ITerminal, opts?: stream.ReadableOptions) {
         super(opts);
-        this.terminal.on('data', (data: any) => {
-            this.push(data);
-        });
+        this.terminal.on('data', data => this.push(data));
     }
+
     /* This needs to be implemented as per node's API doc, even if it's empty.  */
     _read(size: number) {
     }
+
+}
+
+class TerminalWritableStream extends stream.Writable {
+
+    constructor(protected readonly terminal: ITerminal) {
+        super({
+            write: (chunk, encoding, next) => {
+                this.terminal.write(chunk.toString());
+                next();
+            }
+        });
+    }
+
 }
 
 @injectable()
 export class TerminalProcess extends Process {
 
-    readonly output: TerminalReadableStream;
+    readonly input: stream.Writable;
+    readonly output: stream.Readable;
     protected readonly terminal: ITerminal;
 
     constructor(
@@ -59,6 +74,7 @@ export class TerminalProcess extends Process {
 
         this.terminal.on('exit', this.emitOnExit.bind(this));
         this.output = new TerminalReadableStream(this.terminal);
+        this.input = new TerminalWritableStream(this.terminal);
     }
 
     get pid() {