diff --git a/tools/viewer/sk_app/unix/GLWindowContext_unix.cpp b/tools/viewer/sk_app/unix/GLWindowContext_unix.cpp
new file mode 100644
index 0000000..19f9731
--- /dev/null
+++ b/tools/viewer/sk_app/unix/GLWindowContext_unix.cpp
@@ -0,0 +1,99 @@
+
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GLWindowContext_unix.h"
+
+#include <GL/gl.h>
+
+#include "Window_unix.h"
+
+namespace sk_app {
+
+// platform-dependent create
+GLWindowContext* GLWindowContext::Create(void* platformData, const DisplayParams& params) {
+    GLWindowContext_unix* ctx = new GLWindowContext_unix(platformData, params);
+    if (!ctx->isValid()) {
+        delete ctx;
+        return nullptr;
+    }
+    return ctx;
+}
+
+GLWindowContext_unix::GLWindowContext_unix(void* platformData, const DisplayParams& params)
+    : GLWindowContext(platformData, params)
+    , fDisplay(nullptr)
+    , fWindow(0)
+    , fGLContext(0) {
+
+    // any config code here (particularly for msaa)?
+
+    this->initializeContext(platformData, params);
+}
+
+GLWindowContext_unix::~GLWindowContext_unix() {
+    this->destroyContext();
+}
+
+void GLWindowContext_unix::onInitializeContext(void* platformData, const DisplayParams& params) {
+    ContextPlatformData_unix* unixPlatformData =
+        reinterpret_cast<ContextPlatformData_unix*>(platformData);
+
+    if (unixPlatformData) {
+        fDisplay = unixPlatformData->fDisplay;
+        fWindow = unixPlatformData->fWindow;
+        fVisualInfo = unixPlatformData->fVisualInfo;
+    }
+    SkASSERT(fDisplay);
+
+    fGLContext = glXCreateContext(fDisplay, fVisualInfo, nullptr, GL_TRUE);
+    if (!fGLContext) {
+        return;
+    }
+
+    if (glXMakeCurrent(fDisplay, fWindow, fGLContext)) {
+        glClearStencil(0);
+        glClearColor(0, 0, 0, 0);
+        glStencilMask(0xffffffff);
+        glClear(GL_STENCIL_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
+
+        int redBits, greenBits, blueBits;
+        glXGetConfig(fDisplay, fVisualInfo, GLX_RED_SIZE, &redBits);
+        glXGetConfig(fDisplay, fVisualInfo, GLX_GREEN_SIZE, &greenBits);
+        glXGetConfig(fDisplay, fVisualInfo, GLX_BLUE_SIZE, &blueBits);
+        fColorBits = redBits + greenBits + blueBits;
+        glXGetConfig(fDisplay, fVisualInfo, GLX_STENCIL_SIZE, &fStencilBits);
+        glXGetConfig(fDisplay, fVisualInfo, GLX_SAMPLES_ARB, &fSampleCount);
+
+        XWindow root;
+        int x, y;
+        unsigned int border_width, depth;
+        XGetGeometry(fDisplay, fWindow, &root, &x, &y,
+                     (unsigned int*)&fWidth, (unsigned int*)&fHeight, &border_width, &depth); 
+        glViewport(0, 0, fWidth, fHeight);
+    }
+}
+
+void GLWindowContext_unix::onDestroyContext() {
+    if (!fDisplay || !fGLContext) {
+        return;
+    }
+    glXMakeCurrent(fDisplay, None, nullptr);
+    glXDestroyContext(fDisplay, fGLContext);
+    fGLContext = nullptr;
+}
+
+
+void GLWindowContext_unix::onSwapBuffers() {
+    if (fDisplay && fGLContext) {
+        printf("swapping\n");
+        glXSwapBuffers(fDisplay, fWindow);
+    }
+}
+
+
+}   //namespace sk_app
diff --git a/tools/viewer/sk_app/unix/GLWindowContext_unix.h b/tools/viewer/sk_app/unix/GLWindowContext_unix.h
new file mode 100644
index 0000000..2d76254c
--- /dev/null
+++ b/tools/viewer/sk_app/unix/GLWindowContext_unix.h
@@ -0,0 +1,39 @@
+
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef GLWindowContext_unix_DEFINED
+#define GLWindowContext_unix_DEFINED
+
+#include "../GLWindowContext.h"
+#include "Window_unix.h"
+
+namespace sk_app {
+
+class GLWindowContext_unix : public GLWindowContext {
+public:
+    friend GLWindowContext* GLWindowContext::Create(void* platformData, const DisplayParams&);
+
+    ~GLWindowContext_unix() override;
+
+    void onSwapBuffers() override;
+
+    void onInitializeContext(void*, const DisplayParams&) override;
+    void onDestroyContext() override;
+
+private:
+    GLWindowContext_unix(void*, const DisplayParams&);
+
+    Display*     fDisplay;
+    XWindow      fWindow;
+    XVisualInfo* fVisualInfo;
+    GLXContext   fGLContext;
+};
+
+
+}
+
+#endif