diff --git a/CMakeLists.txt b/CMakeLists.txt
index a5273c9..6f67d54 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,6 +22,12 @@ file(GLOB SRCS
     lazperf/detail/*.cpp
 )
 
+
+if(MSVC)
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} \
+        /SUBSYSTEM:WINDOWS /ENTRY:wmainCRTStartup")
+endif()
+
 add_executable(untwine ${SRCS})
 
 untwine_target_compile_settings(untwine)
diff --git a/api/CMakeLists.txt b/api/CMakeLists.txt
index 84b33ee..9031116 100644
--- a/api/CMakeLists.txt
+++ b/api/CMakeLists.txt
@@ -4,7 +4,7 @@ include(FeatureSummary)
 include(${PROJECT_SOURCE_DIR}/../cmake/compiler_options.cmake)
 
 add_executable(qgt
-    QgisTest.cpp
+    QgisTest2.cpp
     QgisUntwine.cpp
 )
 
diff --git a/api/QgisTest2.cpp b/api/QgisTest2.cpp
new file mode 100644
index 0000000..b3593f7
--- /dev/null
+++ b/api/QgisTest2.cpp
@@ -0,0 +1,43 @@
+#ifndef _WIN32
+#include <unistd.h>
+#endif
+
+#include <iostream>
+
+#include "QgisUntwine.hpp"
+
+int main()
+{
+    untwine::QgisUntwine::StringList files;
+    untwine::QgisUntwine::Options options;
+    std::string exe = "C:\\Users\\andre\\untwine\\build\\untwine.exe";
+
+    untwine::QgisUntwine api(exe);
+    
+    std::vector<unsigned char> funnycVec = { 0xc4, 0x8d };
+    std::string funnyc(funnycVec.begin(), funnycVec.end());
+    std::string v8string { "C:\\Users\\andre\\untwine\\api\\" + funnyc + "\\" + funnyc + ".las" };
+    files.push_back(v8string);
+    std::string outDir { "./out_" + funnyc };
+    bool ok = api.start(files, outDir, options);
+    if (! ok)
+    {
+        std::cerr << "Couldn't start '" << exe << "!\n";
+        exit(-1);
+    }
+
+    while (true)
+    {
+#ifdef _WIN32
+    	Sleep(1000);
+#else
+        ::sleep(1);
+#endif
+        int percent = api.progressPercent();
+        std::string s = api.progressMessage();
+        std::cerr << "Percent/Msg = " << percent << " / " << s << "!\n";
+        if (!api.running())
+            break;
+    }
+    std::cerr << "Error = " << api.errorMessage() << "\n";
+}
diff --git a/bu/BuPyramid.cpp b/bu/BuPyramid.cpp
index 3740c80..e1efd87 100644
--- a/bu/BuPyramid.cpp
+++ b/bu/BuPyramid.cpp
@@ -3,6 +3,7 @@
 #include <set>
 #include <string>
 #include <vector>
+#include <filesystem>
 
 #include <pdal/util/FileUtils.hpp>
 #include <pdal/util/ProgramArgs.hpp>
@@ -13,6 +14,75 @@
 #include "../untwine/Common.hpp"
 #include "../untwine/ProgressWriter.hpp"
 
+namespace
+{
+
+// PDAL's directoryList had a bug, so we've imported a working
+// version here so that we can still use older PDAL releases.
+
+#ifndef __APPLE_CC__
+std::vector<std::string> directoryList(const std::string& dir)
+{
+    namespace fs = std::filesystem;
+
+    std::vector<std::string> files;
+
+    try
+    {
+        fs::directory_iterator it(untwine::toNative(dir));
+        fs::directory_iterator end;
+        while (it != end)
+        {
+            files.push_back(untwine::fromNative(it->path()));
+            it++;
+        }
+    }
+    catch (fs::filesystem_error&)
+    {
+        files.clear();
+    }
+    return files;
+}
+#else
+
+#include <dirent.h>
+
+// Provide simple opendir/readdir solution for OSX because directory_iterator is
+// not available until OSX 10.15
+std::vector<std::string> directoryList(const std::string& dir)
+{
+
+    DIR *dpdf;
+    struct dirent *epdf;
+
+    std::vector<std::string> files;
+    dpdf = opendir(dir.c_str());
+    if (dpdf != NULL){
+       while ((epdf = readdir(dpdf))){
+            std::string name = untwine::fromNative(epdf->d_name);
+            // Skip paths
+            if (pdal::Utils::iequals(name, ".") ||
+                pdal::Utils::iequals(name, ".."))
+            {
+                continue;
+            }
+            else
+            {
+                // we expect the path + name
+                std::string p = dir + "/" + untwine::fromNative(epdf->d_name);
+                files.push_back(p);
+           }
+       }
+    }
+    closedir(dpdf);
+
+    return files;
+
+}
+#endif
+
+} // unnamed namespace
+
 namespace untwine
 {
 namespace bu
@@ -28,7 +98,9 @@ void BuPyramid::run(ProgressWriter& progress)
 {
     getInputFiles();
     size_t count = queueWork();
-    
+    if (!count)
+        throw FatalError("No temporary files to process. I/O or directory list error?");
+
     progress.setPercent(.6);
     progress.setIncrement(.4 / count);
     m_manager.setProgress(&progress);
@@ -63,7 +135,7 @@ void BuPyramid::writeInfo()
         }
     };
 
-    std::ofstream out(m_b.opts.outputName + "/ept.json");
+    std::ofstream out(toNative(m_b.opts.outputName + "/ept.json"));
     int maxdigits = std::numeric_limits<double>::max_digits10;
 
     out << "{\n";
@@ -164,7 +236,7 @@ void BuPyramid::getInputFiles()
         return std::make_pair(true, VoxelKey(x, y, z, level));
     };
 
-    std::vector<std::string> files = pdal::FileUtils::directoryList(m_b.opts.tempDir);
+    std::vector<std::string> files = directoryList(m_b.opts.tempDir);
 
     VoxelKey root;
     for (std::string file : files)
diff --git a/bu/CopcSupport.cpp b/bu/CopcSupport.cpp
index e6c788d..a630372 100644
--- a/bu/CopcSupport.cpp
+++ b/bu/CopcSupport.cpp
@@ -34,9 +34,9 @@ namespace bu
 CopcSupport::CopcSupport(const BaseInfo& b) : m_b(b),
     m_lazVlr(b.pointFormatId, extraByteSize(), lazperf::VariableChunkSize),
     m_ebVlr(),
-    m_wktVlr(b.srs.getWKT1())
+    m_wktVlr(b.srs.getWKT())
 {
-    m_f.open(b.opts.outputName, std::ios::out | std::ios::binary);
+    m_f.open(toNative(b.opts.outputName), std::ios::out | std::ios::binary);
 
     //ABELL
     m_header.file_source_id = 0;
diff --git a/bu/Processor.cpp b/bu/Processor.cpp
index c780f8a..e7ccd78 100644
--- a/bu/Processor.cpp
+++ b/bu/Processor.cpp
@@ -19,6 +19,7 @@
 #include <pdal/PDALUtils.hpp>
 #include <pdal/StageFactory.hpp>
 #include <pdal/io/BufferReader.hpp>
+#include <pdal/filters/SortFilter.hpp>
 #include <pdal/util/Algorithm.hpp>
 
 #include <lazperf/lazperf.hpp>
@@ -245,7 +246,7 @@ void Processor::writeBinOutput(Index& index)
     // pass.
     std::string filename = m_vi.key().toString() + ".bin";
     std::string fullFilename = m_b.opts.tempDir + "/" + filename;
-    std::ofstream out(fullFilename, std::ios::binary | std::ios::trunc);
+    std::ofstream out(toNative(fullFilename), std::ios::binary | std::ios::trunc);
     if (!out)
         throw FatalError("Couldn't open '" + fullFilename + "' for output.");
     for (size_t i = 0; i < index.size(); ++i)
@@ -416,8 +417,7 @@ void Processor::appendCompressed(pdal::PointViewPtr view, const DimInfoList& dim
     }
 }
 
-void Processor::flushCompressed(pdal::PointViewPtr view, const OctantInfo& oi,
-    IndexedStats& stats)
+void Processor::flushCompressed(pdal::PointViewPtr view, const OctantInfo& oi, IndexedStats& stats)
 {
     // For single file output we need the stats for
     if (m_b.opts.stats)
@@ -490,6 +490,21 @@ void Processor::writeEptFile(const std::string& filename, pdal::PointViewPtr vie
     w->execute(view->table());
 }
 
+void Processor::sortChunk(pdal::PointViewPtr view)
+{
+    pdal::BufferReader r;
+    r.addView(view);
+
+    pdal::SortFilter s;
+    s.setInput(r);
+    pdal::Options o;
+    o.add("dimension", "GpsTime");
+    s.setOptions(o);
+
+    s.prepare(view->table());
+    s.execute(view->table());
+}
+
 void Processor::createChunk(const VoxelKey& key, pdal::PointViewPtr view)
 {
     using namespace pdal;
@@ -502,9 +517,7 @@ void Processor::createChunk(const VoxelKey& key, pdal::PointViewPtr view)
 
     // Sort the chunk on GPS time.
     if (view->layout()->hasDim(Dimension::Id::GpsTime))
-        std::sort(view->begin(), view->end(),
-            [](const PointRef& p1, const PointRef& p2)
-                { return p1.compare(Dimension::Id::GpsTime, p2); });
+        sortChunk(view);
 
     PointLayoutPtr layout = view->layout();
 
@@ -524,7 +537,8 @@ void Processor::createChunk(const VoxelKey& key, pdal::PointViewPtr view)
 
     uint64_t location = m_manager.newChunk(key, chunk.size(), (uint32_t)view->size());
 
-    std::ofstream out(m_b.opts.outputName, std::ios::out | std::ios::in | std::ios::binary);
+    std::ofstream out(toNative(m_b.opts.outputName),
+        std::ios::out | std::ios::in | std::ios::binary);
     out.seekp(std::ofstream::pos_type(location));
     out.write(reinterpret_cast<const char *>(chunk.data()), chunk.size());
     out.close();
diff --git a/bu/Processor.hpp b/bu/Processor.hpp
index 8714aa3..d5d7dce 100644
--- a/bu/Processor.hpp
+++ b/bu/Processor.hpp
@@ -58,6 +58,7 @@ class Processor
     void flushCompressed(pdal::PointViewPtr view, const OctantInfo& oi, IndexedStats& stats);
     void writeEptFile(const std::string& filename, pdal::PointViewPtr view);
     void createChunk(const VoxelKey& key, pdal::PointViewPtr view);
+    void sortChunk(pdal::PointViewPtr view);
     void fillPointBuf(pdal::PointRef& point, std::vector<char>& buf);
 
     VoxelInfo m_vi;
diff --git a/bu/PyramidManager.cpp b/bu/PyramidManager.cpp
index cf78790..f874340 100644
--- a/bu/PyramidManager.cpp
+++ b/bu/PyramidManager.cpp
@@ -234,7 +234,8 @@ std::deque<VoxelKey> PyramidManager::emitRoot(const VoxelKey& root)
     entries.push_back({root, m_written[root]});
     std::deque<VoxelKey> roots = emit(root, stopLevel, entries);
 
-    std::ofstream out(m_b.opts.outputName + "/ept-hierarchy/" + root.toString() + ".json");
+    std::string filename = m_b.opts.outputName + "/ept-hierarchy/" + root.toString() + ".json";
+    std::ofstream out(toNative(filename));
 
     out << "{\n";
 
diff --git a/ci/linux/setup.sh b/ci/linux/setup.sh
index 4a72325..cff7ef4 100755
--- a/ci/linux/setup.sh
+++ b/ci/linux/setup.sh
@@ -3,7 +3,6 @@
 mkdir build
 
 conda update -n base -c defaults conda
-#conda install -c conda-forge cmake ninja compilers -y
-conda install -c conda-forge cmake ninja -y
+conda install -c conda-forge cmake ninja compilers -y
 conda install -c conda-forge --yes --quiet pdal -y
 
diff --git a/epf/Epf.cpp b/epf/Epf.cpp
index 5265f5c..cd45089 100644
--- a/epf/Epf.cpp
+++ b/epf/Epf.cpp
@@ -20,6 +20,7 @@
 #include "../untwine/Las.hpp"
 
 #include <unordered_set>
+#include <filesystem>
 
 #include <pdal/pdal_features.hpp>
 #include <pdal/Dimension.hpp>
@@ -30,6 +31,64 @@
 #include <pdal/util/FileUtils.hpp>
 #include <pdal/util/ProgramArgs.hpp>
 
+
+namespace
+{
+
+// PDAL's directoryList had a bug, so we've imported a working
+// version here so that we can still use older PDAL releases.
+
+#ifndef __APPLE_CC__
+std::vector<std::string> directoryList(const std::string& dir)
+{
+    namespace fs = std::filesystem;
+
+    std::vector<std::string> files;
+
+    try
+    {
+        fs::directory_iterator it(untwine::toNative(dir));
+        fs::directory_iterator end;
+        while (it != end)
+        {
+            files.push_back(untwine::fromNative(it->path()));
+            it++;
+        }
+    }
+    catch (fs::filesystem_error&)
+    {
+        files.clear();
+    }
+    return files;
+}
+#else
+
+#include <dirent.h>
+
+// Provide simple opendir/readdir solution for OSX because directory_iterator is
+// not available until OSX 10.15
+std::vector<std::string> directoryList(const std::string& dir)
+{
+
+    DIR *dpdf;
+    struct dirent *epdf;
+
+    std::vector<std::string> files;
+    dpdf = opendir(dir.c_str());
+    if (dpdf != NULL){
+       while ((epdf = readdir(dpdf))){
+           files.push_back(untwine::fromNative(epdf->d_name));
+       }
+    }
+    closedir(dpdf);
+
+    return files;
+
+}
+#endif
+
+} // unnamed namespace
+
 namespace untwine
 {
 namespace epf
@@ -278,7 +337,7 @@ PointCount Epf::createFileInfo(const StringList& input, StringList dimNames,
     {
         if (FileUtils::isDirectory(filename))
         {
-            std::vector<std::string> dirfiles = FileUtils::directoryList(filename);
+            std::vector<std::string> dirfiles = directoryList(filename);
             filenames.insert(filenames.end(), dirfiles.begin(), dirfiles.end());
         }
         else
diff --git a/epf/Writer.cpp b/epf/Writer.cpp
index 210ed28..50f7343 100644
--- a/epf/Writer.cpp
+++ b/epf/Writer.cpp
@@ -137,7 +137,7 @@ void Writer::run()
 
         // Open the file. Write the data. Stick the buffer back on the cache.
         // Remove the key from the active key list.
-        std::ofstream out(path(wd.key), std::ios::app | std::ios::binary);
+        std::ofstream out(toNative(path(wd.key)), std::ios::app | std::ios::binary);
         out.write(reinterpret_cast<const char *>(wd.data->data()), wd.dataSize);
         out.close();
         if (!out)
diff --git a/untwine/Common.hpp b/untwine/Common.hpp
index 045df24..56a681a 100644
--- a/untwine/Common.hpp
+++ b/untwine/Common.hpp
@@ -1,5 +1,9 @@
 #pragma once
 
+#ifdef _WIN32
+#include <Windows.h>
+#endif
+
 #include <stdint.h>
 #include <array>
 #include <string>
@@ -66,4 +70,50 @@ struct BaseInfo
 
 const std::string MetadataFilename {"info2.txt"};
 
+// We check both _WIN32 and _MSC_VER to deal with MinGW, which doesn't support the special
+// Windows wide character interfaces for streams.
+#if defined(_WIN32) && defined(_MSC_VER)
+inline std::wstring toNative(const std::string& in)
+{
+    if (in.empty())
+        return std::wstring();
+
+    int len = MultiByteToWideChar(CP_UTF8, 0, in.data(), in.length(), nullptr, 0);
+    std::wstring out(len, 0);
+    if (MultiByteToWideChar(CP_UTF8, 0, in.data(), in.length(), out.data(), len) == 0)
+    {
+        char buf[200] {};
+        len = FormatMessageA(0, 0, GetLastError(), 0, buf, 199, 0);
+        throw FatalError("Can't convert UTF8 to UTF16: " + std::string(buf, len));
+    }
+    return out;
+}
+
+inline std::string fromNative(const std::wstring& in)
+{
+    if (in.empty())
+        return std::string();
+
+    int len = WideCharToMultiByte(CP_UTF8, 0, in.data(), in.length(), nullptr, 0, nullptr, nullptr);
+    std::string out(len, 0);
+    if (WideCharToMultiByte(CP_UTF8, 0, in.data(), in.length(), out.data(), len, nullptr, nullptr) == 0)
+    {
+        char buf[200] {};
+        len = FormatMessageA(0, 0, GetLastError(), 0, buf, 199, 0);
+        throw FatalError("Can't convert UTF16 to UTF8: " + std::string(buf, len));
+    }
+    return out;
+}
+#else
+inline std::string toNative(const std::string& in)
+{
+    return in;
+}
+
+inline std::string fromNative(const std::string& in)
+{
+    return in;
+}
+#endif
+
 } // namespace untwine
diff --git a/untwine/MapFile.cpp b/untwine/MapFile.cpp
index 5f517de..90d7e2e 100644
--- a/untwine/MapFile.cpp
+++ b/untwine/MapFile.cpp
@@ -28,13 +28,15 @@
  * OF SUCH DAMAGE.
  ****************************************************************************/
 
+// This is here so that things will work with older version of PDAL.
+
+#include "Common.hpp"
 #include "MapFile.hpp"
 
 namespace untwine
 {
 
-MapContext mapFile(const std::string& filename, bool readOnly,
-    size_t pos, size_t size)
+MapContext mapFile(const std::string& filename, bool readOnly, size_t pos, size_t size)
 {
     MapContext ctx;
 
@@ -45,9 +47,9 @@ MapContext mapFile(const std::string& filename, bool readOnly,
     }
 
 #ifndef _WIN32
-    ctx.m_fd = ::open(filename.c_str(), readOnly ? O_RDONLY : O_RDWR);
+    ctx.m_fd = ::open(filename.data(), readOnly ? O_RDONLY : O_RDWR);
 #else
-    ctx.m_fd = ::_open(filename.c_str(), readOnly ? _O_RDONLY : _O_RDWR);
+    ctx.m_fd = ::_wopen(toNative(filename).data(), readOnly ? _O_RDONLY : _O_RDWR);
 #endif
 
     if (ctx.m_fd == -1)
diff --git a/untwine/MapFile.hpp b/untwine/MapFile.hpp
index 5a73cfa..854907d 100644
--- a/untwine/MapFile.hpp
+++ b/untwine/MapFile.hpp
@@ -28,6 +28,9 @@
  * OF SUCH DAMAGE.
  ****************************************************************************/
 
+//ABELL - This exists here because older version of PDAL don't have it and the QGIS
+//  crew wanted things to work with older versions of PDAL.
+
 #pragma once
 
 #include <fcntl.h>
diff --git a/untwine/ThreadPool.cpp b/untwine/ThreadPool.cpp
index dd7fcc1..d607d43 100644
--- a/untwine/ThreadPool.cpp
+++ b/untwine/ThreadPool.cpp
@@ -32,8 +32,6 @@
  * OF SUCH DAMAGE.
  ****************************************************************************/
 
-#include <iostream>
-
 #include "ThreadPool.hpp"
 
 namespace untwine
diff --git a/untwine/Untwine.cpp b/untwine/Untwine.cpp
index 940207b..cd6c0cf 100644
--- a/untwine/Untwine.cpp
+++ b/untwine/Untwine.cpp
@@ -127,7 +127,11 @@ void createDirs(const Options& options)
 } // namespace untwine
 
 
+#ifdef _WIN32
+int wmain( int argc, wchar_t *argv[ ], wchar_t *envp[ ] )
+#else
 int main(int argc, char *argv[])
+#endif
 {
     std::vector<std::string> arglist;
 
@@ -135,7 +139,7 @@ int main(int argc, char *argv[])
     argv++;
     argc--;
     while (argc--)
-        arglist.push_back(*argv++);
+        arglist.push_back(untwine::fromNative(*argv++));
 
     using namespace untwine;
 
diff --git a/untwine/VoxelKey.hpp b/untwine/VoxelKey.hpp
index 8eeef2e..a29a802 100644
--- a/untwine/VoxelKey.hpp
+++ b/untwine/VoxelKey.hpp
@@ -11,6 +11,7 @@
  ****************************************************************************/
 
 #include <string>
+#include <algorithm>
 
 #pragma once