diff --git a/libraries/gpu-gl/src/gpu/gl/GLBackend.cpp b/libraries/gpu-gl/src/gpu/gl/GLBackend.cpp
index e5460c6641..4d264995ae 100644
--- a/libraries/gpu-gl/src/gpu/gl/GLBackend.cpp
+++ b/libraries/gpu-gl/src/gpu/gl/GLBackend.cpp
@@ -16,7 +16,7 @@
 #include <functional>
 #include <glm/gtc/type_ptr.hpp>
 
-#include "../gl41/GLBackend.h"
+#include "../gl41/GL41Backend.h"
 
 #if defined(NSIGHT_FOUND)
 #include "nvToolsExt.h"
@@ -36,11 +36,11 @@ static const QString DEBUG_FLAG("HIFI_ENABLE_OPENGL_45");
 static bool enableOpenGL45 = QProcessEnvironment::systemEnvironment().contains(DEBUG_FLAG);
 
 Backend* GLBackend::createBackend() {
-    auto version = QOpenGLContextWrapper::currentContextVersion();
 
+#if 0
     // FIXME provide a mechanism to override the backend for testing
     // Where the gpuContext is initialized and where the TRUE Backend is created and assigned
-#if 0
+    auto version = QOpenGLContextWrapper::currentContextVersion();
     GLBackend* result; 
     if (enableOpenGL45 && version >= 0x0405) {
         result = new gpu::gl45::GLBackend;
@@ -48,7 +48,7 @@ Backend* GLBackend::createBackend() {
         result = new gpu::gl41::GLBackend;
     }
 #else 
-    GLBackend* result = new gpu::gl41::GLBackend;
+    GLBackend* result = new gpu::gl41::GL41Backend;
 #endif
     result->initInput();
     result->initTransform();
diff --git a/libraries/gpu-gl/src/gpu/gl/GLQuery.cpp b/libraries/gpu-gl/src/gpu/gl/GLQuery.cpp
deleted file mode 100644
index b358db40c9..0000000000
--- a/libraries/gpu-gl/src/gpu/gl/GLQuery.cpp
+++ /dev/null
@@ -1,12 +0,0 @@
-//
-//  Created by Bradley Austin Davis on 2016/05/15
-//  Copyright 2013-2016 High Fidelity, Inc.
-//
-//  Distributed under the Apache License, Version 2.0.
-//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
-//
-
-#include "GLQuery.h"
-
-using namespace gpu;
-using namespace gpu::gl;
diff --git a/libraries/gpu-gl/src/gpu/gl/GLShared.h b/libraries/gpu-gl/src/gpu/gl/GLShared.h
index 5d90badc1c..3220eafef4 100644
--- a/libraries/gpu-gl/src/gpu/gl/GLShared.h
+++ b/libraries/gpu-gl/src/gpu/gl/GLShared.h
@@ -128,13 +128,6 @@ public:
 
     virtual ~GLObject() { }
 
-    // Used by derived classes and helpers to ensure the actual GL object exceeds the lifetime of `this`
-    GLuint takeOwnership() { 
-        GLuint result = _id;
-        const_cast<GLuint&>(_id) = 0;
-        return result;
-    }
-
     const GPUType& _gpuObject;
     const GLuint _id;
 };
@@ -146,7 +139,6 @@ class GLQuery;
 class GLState;
 class GLShader;
 class GLTexture;
-class GLTextureTransferHelper;
 
 } } // namespace gpu::gl 
 
diff --git a/libraries/gpu-gl/src/gpu/gl/GLTexture.cpp b/libraries/gpu-gl/src/gpu/gl/GLTexture.cpp
index 47fc583d77..ed931437b7 100644
--- a/libraries/gpu-gl/src/gpu/gl/GLTexture.cpp
+++ b/libraries/gpu-gl/src/gpu/gl/GLTexture.cpp
@@ -182,7 +182,7 @@ GLTexture::~GLTexture() {
         if (0 == numTexturesForMipCount) {
             _textureCountByMips.erase(mipCount);
             if (mipCount == _currentMaxMipCount) {
-                _currentMaxMipCount = _textureCountByMips.rbegin()->first;
+                _currentMaxMipCount = (_textureCountByMips.empty() ? 0 : _textureCountByMips.rbegin()->first);
             }
         }
     }
diff --git a/libraries/gpu-gl/src/gpu/gl/GLTexture.h b/libraries/gpu-gl/src/gpu/gl/GLTexture.h
index fa09fb49f2..df2d38e2f3 100644
--- a/libraries/gpu-gl/src/gpu/gl/GLTexture.h
+++ b/libraries/gpu-gl/src/gpu/gl/GLTexture.h
@@ -102,6 +102,13 @@ public:
         return result;
     }
 
+    // Used by derived classes and helpers to ensure the actual GL object exceeds the lifetime of `this`
+    GLuint takeOwnership() {
+        GLuint result = _id;
+        const_cast<GLuint&>(_id) = 0;
+        return result;
+    }
+
     ~GLTexture();
 
     const GLuint& _texture { _id };
diff --git a/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.cpp b/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.cpp
index ca2e7061f5..7acb736063 100644
--- a/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.cpp
+++ b/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.cpp
@@ -13,6 +13,7 @@
 #endif
 
 #include "GLShared.h"
+#include "GLTexture.h"
 
 using namespace gpu;
 using namespace gpu::gl;
diff --git a/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.h b/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.h
index deb470c572..078ab40ee3 100644
--- a/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.h
+++ b/libraries/gpu-gl/src/gpu/gl/GLTextureTransfer.h
@@ -14,7 +14,6 @@
 #include <GenericQueueThread.h>
 
 #include "GLShared.h"
-#include "GLTexture.h"
 
 #ifdef Q_OS_WIN
 #define THREADED_TEXTURE_TRANSFER
diff --git a/libraries/gpu-gl/src/gpu/gl41/GLBackend.cpp b/libraries/gpu-gl/src/gpu/gl41/GL41Backend.cpp
similarity index 93%
rename from libraries/gpu-gl/src/gpu/gl41/GLBackend.cpp
rename to libraries/gpu-gl/src/gpu/gl41/GL41Backend.cpp
index e46c739593..93d87ee6e4 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GLBackend.cpp
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41Backend.cpp
@@ -5,7 +5,7 @@
 //  Distributed under the Apache License, Version 2.0.
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
-#include "GLBackend.h"
+#include "GL41Backend.h"
 
 #include <mutex>
 #include <queue>
@@ -18,7 +18,7 @@ Q_LOGGING_CATEGORY(gpugl41logging, "hifi.gpu.gl41")
 using namespace gpu;
 using namespace gpu::gl41;
 
-void GLBackend::do_draw(Batch& batch, size_t paramOffset) {
+void GL41Backend::do_draw(Batch& batch, size_t paramOffset) {
     Primitive primitiveType = (Primitive)batch._params[paramOffset + 2]._uint;
     GLenum mode = gl::PRIMITIVE_TO_GL[primitiveType];
     uint32 numVertices = batch._params[paramOffset + 1]._uint;
@@ -43,7 +43,7 @@ void GLBackend::do_draw(Batch& batch, size_t paramOffset) {
     (void) CHECK_GL_ERROR();
 }
 
-void GLBackend::do_drawIndexed(Batch& batch, size_t paramOffset) {
+void GL41Backend::do_drawIndexed(Batch& batch, size_t paramOffset) {
     Primitive primitiveType = (Primitive)batch._params[paramOffset + 2]._uint;
     GLenum mode = gl::PRIMITIVE_TO_GL[primitiveType];
     uint32 numIndices = batch._params[paramOffset + 1]._uint;
@@ -72,7 +72,7 @@ void GLBackend::do_drawIndexed(Batch& batch, size_t paramOffset) {
     (void) CHECK_GL_ERROR();
 }
 
-void GLBackend::do_drawInstanced(Batch& batch, size_t paramOffset) {
+void GL41Backend::do_drawInstanced(Batch& batch, size_t paramOffset) {
     GLint numInstances = batch._params[paramOffset + 4]._uint;
     Primitive primitiveType = (Primitive)batch._params[paramOffset + 3]._uint;
     GLenum mode = gl::PRIMITIVE_TO_GL[primitiveType];
@@ -108,7 +108,7 @@ void glbackend_glDrawElementsInstancedBaseVertexBaseInstance(GLenum mode, GLsize
 #endif
 }
 
-void GLBackend::do_drawIndexedInstanced(Batch& batch, size_t paramOffset) {
+void GL41Backend::do_drawIndexedInstanced(Batch& batch, size_t paramOffset) {
     GLint numInstances = batch._params[paramOffset + 4]._uint;
     GLenum mode = gl::PRIMITIVE_TO_GL[(Primitive)batch._params[paramOffset + 3]._uint];
     uint32 numIndices = batch._params[paramOffset + 2]._uint;
@@ -143,7 +143,7 @@ void GLBackend::do_drawIndexedInstanced(Batch& batch, size_t paramOffset) {
 }
 
 
-void GLBackend::do_multiDrawIndirect(Batch& batch, size_t paramOffset) {
+void GL41Backend::do_multiDrawIndirect(Batch& batch, size_t paramOffset) {
 #if (GPU_INPUT_PROFILE == GPU_CORE_43)
     uint commandCount = batch._params[paramOffset + 0]._uint;
     GLenum mode = gl::PRIMITIVE_TO_GL[(Primitive)batch._params[paramOffset + 1]._uint];
@@ -159,7 +159,7 @@ void GLBackend::do_multiDrawIndirect(Batch& batch, size_t paramOffset) {
 
 }
 
-void GLBackend::do_multiDrawIndexedIndirect(Batch& batch, size_t paramOffset) {
+void GL41Backend::do_multiDrawIndexedIndirect(Batch& batch, size_t paramOffset) {
 #if (GPU_INPUT_PROFILE == GPU_CORE_43)
     uint commandCount = batch._params[paramOffset + 0]._uint;
     GLenum mode = gl::PRIMITIVE_TO_GL[(Primitive)batch._params[paramOffset + 1]._uint];
diff --git a/libraries/gpu-gl/src/gpu/gl41/GLBackend.h b/libraries/gpu-gl/src/gpu/gl41/GL41Backend.h
similarity index 86%
rename from libraries/gpu-gl/src/gpu/gl41/GLBackend.h
rename to libraries/gpu-gl/src/gpu/gl41/GL41Backend.h
index 8a0f4bb912..5695ba080e 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GLBackend.h
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41Backend.h
@@ -1,5 +1,5 @@
 //
-//  GLBackend.h
+//  GL41Backend.h
 //  libraries/gpu/src/gpu
 //
 //  Created by Sam Gateau on 10/27/2014.
@@ -8,8 +8,8 @@
 //  Distributed under the Apache License, Version 2.0.
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
-#ifndef hifi_gpu_41_GLBackend_h
-#define hifi_gpu_41_GLBackend_h
+#ifndef hifi_gpu_41_GL41Backend_h
+#define hifi_gpu_41_GL41Backend_h
 
 #include <gl/Config.h>
 
@@ -27,21 +27,21 @@
 
 namespace gpu { namespace gl41 {
 
-class GLBackend : public gl::GLBackend {
+class GL41Backend : public gl::GLBackend {
     using Parent = gl::GLBackend;
     // Context Backend static interface required
     friend class Context;
 
 public:
-    explicit GLBackend(bool syncCache) : Parent(syncCache) {}
-    GLBackend() : Parent() {}
+    explicit GL41Backend(bool syncCache) : Parent(syncCache) {}
+    GL41Backend() : Parent() {}
 
-    class GLTexture : public gpu::gl::GLTexture {
+    class GL41Texture : public gpu::gl::GLTexture {
         using Parent = gpu::gl::GLTexture;
         GLuint allocate();
     public:
-        GLTexture(const Texture& buffer, bool transferrable);
-        GLTexture(const Texture& buffer, GLTexture* original);
+        GL41Texture(const Texture& buffer, bool transferrable);
+        GL41Texture(const Texture& buffer, GL41Texture* original);
 
     protected:
         void transferMip(uint16_t mipLevel, uint8_t face = 0) const;
diff --git a/libraries/gpu-gl/src/gpu/gl41/GLBackendBuffer.cpp b/libraries/gpu-gl/src/gpu/gl41/GL41BackendBuffer.cpp
similarity index 81%
rename from libraries/gpu-gl/src/gpu/gl41/GLBackendBuffer.cpp
rename to libraries/gpu-gl/src/gpu/gl41/GL41BackendBuffer.cpp
index 9c6b8b8124..e56d671891 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GLBackendBuffer.cpp
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41BackendBuffer.cpp
@@ -5,13 +5,13 @@
 //  Distributed under the Apache License, Version 2.0.
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
-#include "GLBackend.h"
+#include "GL41Backend.h"
 #include "../gl/GLBuffer.h"
 
 using namespace gpu;
 using namespace gpu::gl41;
 
-class GLBuffer : public gl::GLBuffer {
+class GL41Buffer : public gl::GLBuffer {
     using Parent = gpu::gl::GLBuffer;
     static GLuint allocate() {
         GLuint result;
@@ -20,7 +20,7 @@ class GLBuffer : public gl::GLBuffer {
     }
 
 public:
-    GLBuffer(const Buffer& buffer, GLBuffer* original) : Parent(buffer, allocate()) {
+    GL41Buffer(const Buffer& buffer, GL41Buffer* original) : Parent(buffer, allocate()) {
         glBindBuffer(GL_ARRAY_BUFFER, _buffer);
         glBufferData(GL_ARRAY_BUFFER, _size, nullptr, GL_DYNAMIC_DRAW);
         glBindBuffer(GL_ARRAY_BUFFER, 0);
@@ -53,10 +53,10 @@ public:
     }
 };
 
-GLuint GLBackend::getBufferID(const Buffer& buffer) {
-    return GLBuffer::getId<GLBuffer>(buffer);
+GLuint GL41Backend::getBufferID(const Buffer& buffer) {
+    return GL41Buffer::getId<GL41Buffer>(buffer);
 }
 
-gl::GLBuffer* GLBackend::syncGPUObject(const Buffer& buffer) {
-    return GLBuffer::sync<GLBuffer>(buffer);
+gl::GLBuffer* GL41Backend::syncGPUObject(const Buffer& buffer) {
+    return GL41Buffer::sync<GL41Buffer>(buffer);
 }
diff --git a/libraries/gpu-gl/src/gpu/gl41/GLBackendInput.cpp b/libraries/gpu-gl/src/gpu/gl41/GL41BackendInput.cpp
similarity index 96%
rename from libraries/gpu-gl/src/gpu/gl41/GLBackendInput.cpp
rename to libraries/gpu-gl/src/gpu/gl41/GL41BackendInput.cpp
index 0486d1cfd2..1b0caa7345 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GLBackendInput.cpp
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41BackendInput.cpp
@@ -1,5 +1,5 @@
 //
-//  GLBackendInput.cpp
+//  GL41BackendInput.cpp
 //  libraries/gpu/src/gpu
 //
 //  Created by Sam Gateau on 3/8/2015.
@@ -8,7 +8,7 @@
 //  Distributed under the Apache License, Version 2.0.
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
-#include "GLBackend.h"
+#include "GL41Backend.h"
 
 using namespace gpu;
 using namespace gpu::gl41;
@@ -22,7 +22,7 @@ using namespace gpu::gl41;
 #define SUPPORT_VERTEX_ATTRIB_FORMAT
 #endif
 
-void GLBackend::updateInput() {
+void GL41Backend::updateInput() {
 #if defined(SUPPORT_VERTEX_ATTRIB_FORMAT)
     if (_input._invalidFormat) {
 
@@ -36,7 +36,7 @@ void GLBackend::updateInput() {
                 GLuint slot = attrib._slot;
                 GLuint count = attrib._element.getLocationScalarCount();
                 uint8_t locationCount = attrib._element.getLocationCount();
-                GLenum type = _elementTypeToGLType[attrib._element.getType()];
+                GLenum type = _elementTypeToGL41Type[attrib._element.getType()];
                 GLuint offset = attrib._offset;;
                 GLboolean isNormalized = attrib._element.isNormalized();
 
@@ -142,7 +142,7 @@ void GLBackend::updateInput() {
                     int bufferNum = (channelIt).first;
 
                     if (_input._invalidBuffers.test(bufferNum) || _input._invalidFormat) {
-                      //  GLuint vbo = gpu::GLBackend::getBufferID((*buffers[bufferNum]));
+                      //  GLuint vbo = gpu::GL41Backend::getBufferID((*buffers[bufferNum]));
                         GLuint vbo = _input._bufferVBOs[bufferNum];
                         if (boundVBO != vbo) {
                             glBindBuffer(GL_ARRAY_BUFFER, vbo);
diff --git a/libraries/gpu-gl/src/gpu/gl41/GLBackendOutput.cpp b/libraries/gpu-gl/src/gpu/gl41/GL41BackendOutput.cpp
similarity index 86%
rename from libraries/gpu-gl/src/gpu/gl41/GLBackendOutput.cpp
rename to libraries/gpu-gl/src/gpu/gl41/GL41BackendOutput.cpp
index a34a0aaebd..53c2c75394 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GLBackendOutput.cpp
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41BackendOutput.cpp
@@ -1,5 +1,5 @@
 //
-//  GLBackendTexture.cpp
+//  GL41BackendTexture.cpp
 //  libraries/gpu/src/gpu
 //
 //  Created by Sam Gateau on 1/19/2015.
@@ -8,7 +8,7 @@
 //  Distributed under the Apache License, Version 2.0.
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
-#include "GLBackend.h"
+#include "GL41Backend.h"
 
 #include <QtGui/QImage>
 
@@ -17,7 +17,7 @@
 
 namespace gpu { namespace gl41 { 
 
-class GLFramebuffer : public gl::GLFramebuffer {
+class GL41Framebuffer : public gl::GLFramebuffer {
     using Parent = gl::GLFramebuffer;
     static GLuint allocate() {
         GLuint result;
@@ -56,7 +56,7 @@ public:
                 for (auto& b : _gpuObject.getRenderBuffers()) {
                     surface = b._texture;
                     if (surface) {
-                        gltexture = gl::GLTexture::sync<GLBackend::GLTexture>(surface, false); // Grab the gltexture and don't transfer
+                        gltexture = gl::GLTexture::sync<GL41Backend::GL41Texture>(surface, false); // Grab the gltexture and don't transfer
                     } else {
                         gltexture = nullptr;
                     }
@@ -83,7 +83,7 @@ public:
         if (_gpuObject.getDepthStamp() != _depthStamp) {
             auto surface = _gpuObject.getDepthStencilBuffer();
             if (_gpuObject.hasDepthStencil() && surface) {
-                gltexture = gl::GLTexture::sync<GLBackend::GLTexture>(surface, false); // Grab the gltexture and don't transfer
+                gltexture = gl::GLTexture::sync<GL41Backend::GL41Texture>(surface, false); // Grab the gltexture and don't transfer
             }
 
             if (gltexture) {
@@ -115,19 +115,19 @@ public:
 
 
 public:
-    GLFramebuffer(const gpu::Framebuffer& framebuffer) 
+    GL41Framebuffer(const gpu::Framebuffer& framebuffer) 
         : Parent(framebuffer, allocate()) { }
 };
 
-gl::GLFramebuffer* GLBackend::syncGPUObject(const Framebuffer& framebuffer) {
-    return GLFramebuffer::sync<GLFramebuffer>(framebuffer);
+gl::GLFramebuffer* GL41Backend::syncGPUObject(const Framebuffer& framebuffer) {
+    return GL41Framebuffer::sync<GL41Framebuffer>(framebuffer);
 }
 
-GLuint GLBackend::getFramebufferID(const FramebufferPointer& framebuffer) {
-    return framebuffer ? GLFramebuffer::getId<GLFramebuffer>(*framebuffer) : 0;
+GLuint GL41Backend::getFramebufferID(const FramebufferPointer& framebuffer) {
+    return framebuffer ? GL41Framebuffer::getId<GL41Framebuffer>(*framebuffer) : 0;
 }
 
-void GLBackend::do_blit(Batch& batch, size_t paramOffset) {
+void GL41Backend::do_blit(Batch& batch, size_t paramOffset) {
     auto srcframebuffer = batch._framebuffers.get(batch._params[paramOffset]._uint);
     Vec4i srcvp;
     for (auto i = 0; i < 4; ++i) {
diff --git a/libraries/gpu-gl/src/gpu/gl41/GLBackendQuery.cpp b/libraries/gpu-gl/src/gpu/gl41/GL41BackendQuery.cpp
similarity index 62%
rename from libraries/gpu-gl/src/gpu/gl41/GLBackendQuery.cpp
rename to libraries/gpu-gl/src/gpu/gl41/GL41BackendQuery.cpp
index 4915adbc1d..3c6109bbdf 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GLBackendQuery.cpp
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41BackendQuery.cpp
@@ -1,5 +1,5 @@
 //
-//  GLBackendQuery.cpp
+//  GL41BackendQuery.cpp
 //  libraries/gpu/src/gpu
 //
 //  Created by Sam Gateau on 7/7/2015.
@@ -8,14 +8,14 @@
 //  Distributed under the Apache License, Version 2.0.
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
-#include "GLBackend.h"
+#include "GL41Backend.h"
 
 #include "../gl/GLQuery.h"
 
 using namespace gpu;
 using namespace gpu::gl41; 
 
-class GLQuery : public gpu::gl::GLQuery {
+class GL41Query : public gpu::gl::GLQuery {
     using Parent = gpu::gl::GLBuffer;
 public:
     static GLuint allocateQuery() {
@@ -24,14 +24,14 @@ public:
         return result;
     }
 
-    GLQuery(const Query& query) 
+    GL41Query(const Query& query) 
         : gl::GLQuery(query, allocateQuery()) { }
 };
 
-gl::GLQuery* GLBackend::syncGPUObject(const Query& query) {
-    return GLQuery::sync<GLQuery>(query);
+gl::GLQuery* GL41Backend::syncGPUObject(const Query& query) {
+    return GL41Query::sync<GL41Query>(query);
 }
 
-GLuint GLBackend::getQueryID(const QueryPointer& query) {
-    return GLQuery::getId<GLQuery>(query);
+GLuint GL41Backend::getQueryID(const QueryPointer& query) {
+    return GL41Query::getId<GL41Query>(query);
 }
diff --git a/libraries/gpu-gl/src/gpu/gl41/GLBackendTexture.cpp b/libraries/gpu-gl/src/gpu/gl41/GL41BackendTexture.cpp
similarity index 86%
rename from libraries/gpu-gl/src/gpu/gl41/GLBackendTexture.cpp
rename to libraries/gpu-gl/src/gpu/gl41/GL41BackendTexture.cpp
index f5e8531ddc..326a63c01a 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GLBackendTexture.cpp
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41BackendTexture.cpp
@@ -1,5 +1,5 @@
 //
-//  GLBackendTexture.cpp
+//  GL41BackendTexture.cpp
 //  libraries/gpu/src/gpu
 //
 //  Created by Sam Gateau on 1/19/2015.
@@ -8,7 +8,7 @@
 //  Distributed under the Apache License, Version 2.0.
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
-#include "GLBackend.h"
+#include "GL41Backend.h"
 
 #include <unordered_set>
 #include <unordered_map>
@@ -19,29 +19,29 @@
 using namespace gpu;
 using namespace gpu::gl41;
 
-using GLTexelFormat = gl::GLTexelFormat;
-using GLTexture = GLBackend::GLTexture;
+using GL41TexelFormat = gl::GLTexelFormat;
+using GL41Texture = GL41Backend::GL41Texture;
 
-GLuint GLTexture::allocate() {
+GLuint GL41Texture::allocate() {
     Backend::incrementTextureGPUCount();
     GLuint result;
     glGenTextures(1, &result);
     return result;
 }
 
-GLuint GLBackend::getTextureID(const TexturePointer& texture, bool transfer) {
-    return GLTexture::getId<GLTexture>(texture, transfer);
+GLuint GL41Backend::getTextureID(const TexturePointer& texture, bool transfer) {
+    return GL41Texture::getId<GL41Texture>(texture, transfer);
 }
 
-gl::GLTexture* GLBackend::syncGPUObject(const TexturePointer& texture, bool transfer) {
-    return GLTexture::sync<GLTexture>(texture, transfer);
+gl::GLTexture* GL41Backend::syncGPUObject(const TexturePointer& texture, bool transfer) {
+    return GL41Texture::sync<GL41Texture>(texture, transfer);
 }
 
-GLTexture::GLTexture(const Texture& texture, bool transferrable) : gl::GLTexture(texture, allocate(), transferrable) {}
+GL41Texture::GL41Texture(const Texture& texture, bool transferrable) : gl::GLTexture(texture, allocate(), transferrable) {}
 
-GLTexture::GLTexture(const Texture& texture, GLTexture* original) : gl::GLTexture(texture, allocate(), original) {}
+GL41Texture::GL41Texture(const Texture& texture, GL41Texture* original) : gl::GLTexture(texture, allocate(), original) {}
 
-void GLBackend::GLTexture::withPreservedTexture(std::function<void()> f) const  {
+void GL41Backend::GL41Texture::withPreservedTexture(std::function<void()> f) const  {
     GLint boundTex = -1;
     switch (_target) {
     case GL_TEXTURE_2D:
@@ -63,14 +63,14 @@ void GLBackend::GLTexture::withPreservedTexture(std::function<void()> f) const
     (void)CHECK_GL_ERROR();
 }
 
-void GLBackend::GLTexture::generateMips() const {
+void GL41Backend::GL41Texture::generateMips() const {
     withPreservedTexture([&] {
         glGenerateMipmap(_target);
     });
     (void)CHECK_GL_ERROR();
 }
 
-void GLBackend::GLTexture::allocateStorage() const {
+void GL41Backend::GL41Texture::allocateStorage() const {
     gl::GLTexelFormat texelFormat = gl::GLTexelFormat::evalGLTexelFormat(_gpuObject.getTexelFormat());
     glTexParameteri(_target, GL_TEXTURE_BASE_LEVEL, 0);
     (void)CHECK_GL_ERROR();
@@ -93,7 +93,7 @@ void GLBackend::GLTexture::allocateStorage() const {
     }
 }
 
-void GLBackend::GLTexture::updateSize() const {
+void GL41Backend::GL41Texture::updateSize() const {
     setSize(_virtualSize);
     if (!_id) {
         return;
@@ -129,7 +129,7 @@ void GLBackend::GLTexture::updateSize() const {
 }
 
 // Move content bits from the CPU to the GPU for a given mip / face
-void GLBackend::GLTexture::transferMip(uint16_t mipLevel, uint8_t face) const {
+void GL41Backend::GL41Texture::transferMip(uint16_t mipLevel, uint8_t face) const {
     auto mip = _gpuObject.accessStoredMipFace(mipLevel, face);
     gl::GLTexelFormat texelFormat = gl::GLTexelFormat::evalGLTexelFormat(_gpuObject.getTexelFormat(), mip->getFormat());
     //GLenum target = getFaceTargets()[face];
@@ -141,7 +141,7 @@ void GLBackend::GLTexture::transferMip(uint16_t mipLevel, uint8_t face) const {
 
 // This should never happen on the main thread
 // Move content bits from the CPU to the GPU
-void GLBackend::GLTexture::transfer() const {
+void GL41Backend::GL41Texture::transfer() const {
     PROFILE_RANGE(__FUNCTION__);
     //qDebug() << "Transferring texture: " << _privateTexture;
     // Need to update the content of the GPU object from the source sysmem of the texture
@@ -208,11 +208,8 @@ void GLBackend::GLTexture::transfer() const {
     }
 }
 
-void GLBackend::GLTexture::syncSampler() const {
+void GL41Backend::GL41Texture::syncSampler() const {
     const Sampler& sampler = _gpuObject.getSampler();
-    Texture::Type type = _gpuObject.getType();
-    auto object = this;
-
     const auto& fm = FILTER_MODES[sampler.getFilter()];
     glTexParameteri(_target, GL_TEXTURE_MIN_FILTER, fm.minFilter);
     glTexParameteri(_target, GL_TEXTURE_MAG_FILTER, fm.magFilter);
diff --git a/libraries/gpu-gl/src/gpu/gl41/GLBackendTransform.cpp b/libraries/gpu-gl/src/gpu/gl41/GL41BackendTransform.cpp
similarity index 95%
rename from libraries/gpu-gl/src/gpu/gl41/GLBackendTransform.cpp
rename to libraries/gpu-gl/src/gpu/gl41/GL41BackendTransform.cpp
index 6601eef86e..89b5db34c0 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GLBackendTransform.cpp
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41BackendTransform.cpp
@@ -1,5 +1,5 @@
 //
-//  GLBackendTransform.cpp
+//  GL41BackendTransform.cpp
 //  libraries/gpu/src/gpu
 //
 //  Created by Sam Gateau on 3/8/2015.
@@ -8,12 +8,12 @@
 //  Distributed under the Apache License, Version 2.0.
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
-#include "GLBackend.h"
+#include "GL41Backend.h"
 
 using namespace gpu;
 using namespace gpu::gl41;
 
-void GLBackend::initTransform() {
+void GL41Backend::initTransform() {
     glGenBuffers(1, &_transform._objectBuffer);
     glGenBuffers(1, &_transform._cameraBuffer);
     glGenBuffers(1, &_transform._drawCallInfoBuffer);
@@ -24,7 +24,7 @@ void GLBackend::initTransform() {
     }
 }
 
-void GLBackend::transferTransformState(const Batch& batch) const {
+void GL41Backend::transferTransformState(const Batch& batch) const {
     // FIXME not thread safe
     static std::vector<uint8_t> bufferData;
     if (!_transform._cameras.empty()) {
diff --git a/libraries/gpu/src/gpu/Forward.h b/libraries/gpu/src/gpu/Forward.h
index 83645f73e3..7fe6739ff7 100644
--- a/libraries/gpu/src/gpu/Forward.h
+++ b/libraries/gpu/src/gpu/Forward.h
@@ -87,11 +87,11 @@ namespace gpu {
     }
 
     namespace gl41 {
-        class GLBackend;
+        class GL41Backend;
     }
 
     namespace gl45 {
-        class GLBackend;
+        class GL45Backend;
     }
 }