diff --git a/mario/filesystem.hpp b/mario/filesystem.hpp
new file mode 100644
index 0000000..7a71f62
--- /dev/null
+++ b/mario/filesystem.hpp
@@ -0,0 +1,127 @@
+#ifndef FSLIB_H
+#define FSLIB_H
+
+#include <string>
+
+#ifdef _WIN32
+
+#include <Windows.h>
+
+using string = std::wstring;
+using char_t = wchar_t;
+
+#else
+
+#include <dirent.h>
+
+using string = std::string;
+using char_t = char;
+
+#endif
+
+// windows version stolen from
+// http://www.martinbroadhurst.com/list-the-files-in-a-directory-in-c.html
+
+namespace FSLib {
+
+bool exists( const string &path );
+bool isDirectory( const string &path );
+bool rename( const string &file_a, const string &file_b );
+bool deleteFile( const string &file );
+string canonical( const string &path );
+bool createDirectoryFull( const string &path );
+string getContainingDirectory( const string &path );
+string getFileName( const string &path );
+string getFileExtension( const string &path );
+extern char dir_divisor;
+
+class Directory {
+public:
+    Directory() = delete;
+    explicit Directory( const string &path_ );
+    explicit Directory( const Directory &d ) = default;
+    explicit Directory( Directory &&d ) = default;
+
+    class Iterator {
+    public:
+        explicit Iterator( const Directory &d_ );
+        ~Iterator();
+
+#ifdef _WIN32
+        explicit Iterator( bool ended_ );
+#else
+        Iterator( const Directory &d_, const struct dirent *current_entry_ );
+#endif
+
+        Iterator() = delete;
+
+        Iterator( const Iterator &i ) = default;
+
+        Iterator( Iterator &&i ) = default;
+
+        char_t const *operator*() const;
+
+        Iterator &operator++();
+
+        bool operator==( const Iterator &i_other ) const;
+
+        Iterator operator++( int ) {
+            Iterator ret( *this );
+            operator++();
+            return ret;
+        }
+
+        bool operator!=( const Iterator &i_other ) const {
+            return !( i_other == *this );
+        }
+
+    private:
+#ifndef _WIN32
+        DIR *d{};
+        const struct dirent *current_entry{};
+#else
+        HANDLE hFind{};
+        WIN32_FIND_DATA data{};
+        bool ended{ false };
+#endif
+    };
+
+    using iterator = Iterator;
+    using const_iterator = Iterator;
+
+    iterator end();
+
+    const_iterator end() const;
+
+    iterator begin() {
+        return Iterator( *this );
+    }
+
+    const_iterator begin() const {
+        return Iterator( *this );
+    }
+
+    const_iterator cbegin() const {
+        return begin();
+    }
+
+    const_iterator cend() const {
+        return end();
+    }
+
+    const char_t *path() const {
+        return dir_path.c_str();
+    }
+
+#ifdef _WIN32
+    const char_t *validPath() const {
+        return dir_path.substr( 0, dir_path.length() - 2 ).c_str();
+    }
+#endif
+
+private:
+    string dir_path;
+};
+} // namespace FSLib
+
+#endif
diff --git a/mario/filesystem/unix/filesystem.cpp b/mario/filesystem/unix/filesystem.cpp
new file mode 100644
index 0000000..32db164
--- /dev/null
+++ b/mario/filesystem/unix/filesystem.cpp
@@ -0,0 +1,174 @@
+#include "../../filesystem.hpp"
+#include <cstring>
+#include <sys/stat.h>
+#include <unistd.h>
+#ifdef __APPLE__
+#include <sys/syslimits.h>
+#endif
+#include <stdexcept>
+#include <iostream>
+
+char FSLib::dir_divisor = '/';
+
+FSLib::Directory::Directory( const string &path_ ) : dir_path( path_ ) {}
+
+FSLib::Directory::Iterator::Iterator( const Directory &d_ )
+        : d( opendir( d_.path() ) ) {
+    if ( !exists( d_.path() ) || !isDirectory( d_.path() ) ) {
+        throw std::runtime_error(
+            std::string( "Directory " ) + d_.path() +
+            " either doesn't exist or isn't a directory" );
+    }
+
+    current_entry = readdir( d );
+
+    // skip "." and ".."
+    if ( current_entry != nullptr &&
+         ( !strcmp( current_entry->d_name, "." ) ||
+           !strcmp( current_entry->d_name, ".." ) ) )
+        ++( *this );
+}
+
+FSLib::Directory::Iterator::Iterator( const Directory &d_,
+                                      const struct dirent *current_entry_ )
+        : d( opendir( d_.path() ) ), current_entry( current_entry_ ) {}
+
+FSLib::Directory::Iterator::~Iterator() {
+    if ( d )
+        closedir( d );
+}
+
+bool FSLib::exists( const string &path ) {
+    struct stat path_stat;
+    return stat( path.c_str(), &path_stat ) == 0;
+}
+
+string FSLib::canonical( const string &path ) {
+    char_t *canonical_path = new char_t[PATH_MAX];
+    auto failed = realpath( path.c_str(), canonical_path ) == nullptr;
+
+    if ( failed ) {
+        delete[] canonical_path;
+        return string();
+    }
+
+    string canonical_string{ canonical_path };
+    delete[] canonical_path;
+    return canonical_string;
+}
+
+bool FSLib::isDirectory( const string &path ) {
+    struct stat path_stat;
+
+    if ( stat( path.c_str(), &path_stat ) != 0 )
+        return false;
+
+    return S_ISDIR( path_stat.st_mode );
+}
+
+bool FSLib::rename( const string &file_a, const string &file_b ) {
+    // TODO log
+    std::cout << file_a << " -> " << file_b << std::endl;
+    return ::rename( file_a.c_str(), file_b.c_str() ) == 0;
+}
+
+// TODO do windows version
+bool deleteRecursive(const string &dir) {
+    for(const auto &file : FSLib::Directory(dir)) {
+        auto path = dir + "/" + file;
+        if(FSLib::isDirectory(path)) {
+            if(!deleteRecursive(path)) {
+                return false;
+            }
+        } else if(unlink(path.c_str()) != 0) {
+            return false;
+        }
+    }
+    return rmdir(dir.c_str()) == 0;
+}
+
+bool FSLib::deleteFile( const string &file ) {
+    // TODO log
+    auto canon = canonical( file );
+    if(canon.empty()) {
+        return false;
+    }
+
+    if(isDirectory(canon)) {
+        return deleteRecursive(canon);
+    }
+    return unlink(canon.c_str()) == 0;
+}
+
+bool FSLib::createDirectoryFull( const string &path ) {
+    uint64_t pos{};
+    // go through all directories leading to the last one
+    // and create them if they don't exist
+    do {
+        // get partial directory path
+        pos = path.find_first_of( "/", pos );
+        if ( pos > 0 ) {
+            auto dirname = path.substr( 0, pos );
+            // create it if it doesn't exist
+            if ( !FSLib::exists( dirname ) ) {
+                if ( mkdir( dirname.c_str(),
+                            S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH ) != 0 )
+                    return false;
+            }
+        }
+        pos++;
+    } while ( pos < path.length() && pos != 0 );
+    return true;
+}
+
+FSLib::Directory::iterator FSLib::Directory::end() {
+    return Iterator( *this, nullptr );
+}
+
+FSLib::Directory::const_iterator FSLib::Directory::end() const {
+    return Iterator( *this, nullptr );
+}
+
+char_t const *FSLib::Directory::Iterator::operator*() const {
+    return current_entry->d_name;
+}
+
+FSLib::Directory::Iterator &FSLib::Directory::Iterator::operator++() {
+    if ( current_entry == nullptr )
+        return *this;
+    current_entry = readdir( d );
+    // skip . and ..
+    if ( current_entry != nullptr &&
+         ( !strcmp( current_entry->d_name, "." ) ||
+           !strcmp( current_entry->d_name, ".." ) ) )
+        return operator++();
+    return *this;
+}
+
+bool FSLib::Directory::Iterator::operator==( const Iterator &i_other ) const {
+    return i_other.current_entry == current_entry;
+}
+
+string FSLib::getContainingDirectory( const string &path ) {
+    auto pos = path.find_last_of('/');
+    if(pos == string::npos) {
+        return ".";
+    }
+    return path.substr(0, pos);
+}
+
+string FSLib::getFileName( const string &path ) {
+    auto pos = path.find_last_of('/');
+    if(pos == string::npos) {
+        return path;
+    }
+    return path.substr(pos+1);
+}
+
+string FSLib::getFileExtension( const string &path ) {
+    auto pos = path.find_last_of('.');
+    if(pos == string::npos) {
+        return "";
+    }
+    return path.substr(pos + 1);
+}
diff --git a/mario/filesystem/windows/filesystem.cpp b/mario/filesystem/windows/filesystem.cpp
new file mode 100644
index 0000000..098d115
--- /dev/null
+++ b/mario/filesystem/windows/filesystem.cpp
@@ -0,0 +1,156 @@
+#include "../../filesystem.hpp"
+#include <Shlwapi.h>
+#include <cstring>
+#include <stdexcept>
+#include <windows.h>
+
+char FSLib::dir_divisor = '\\';
+
+FSLib::Directory::Directory( const string &path_ ) : dir_path( path_ ) {
+    // need to append \\* for windows to search files in directory
+    dir_path.append( L"\\*" );
+}
+
+FSLib::Directory::Iterator::Iterator( const Directory &d_ ) {
+    if ( !exists( d_.validPath() ) || !isDirectory( d_.validPath() ) ) {
+        throw std::runtime_error(
+            "Directory either doesn't exist or isn't a directory" );
+    }
+    hFind = FindFirstFileW( d_.path(), &data );
+    if ( hFind != INVALID_HANDLE_VALUE ) {
+        if ( !wcscmp( data.cFileName, L"." ) ||
+             !wcscmp( data.cFileName, L".." ) ) {
+            ++( *this );
+        }
+    } else {
+        ended = true;
+    }
+}
+
+FSLib::Directory::Iterator::~Iterator() {
+    if ( hFind )
+        FindClose( hFind );
+}
+
+// this is definitely not a good way to create the "end" iterator
+// but it was the only way I thought of with my limited knowledge of
+// windows.h
+FSLib::Directory::Iterator::Iterator( bool ended_ ) : ended( ended_ ) {}
+
+bool FSLib::exists( const string &path ) {
+    struct _stat path_stat;
+    return _wstat( path.c_str(), &path_stat ) == 0;
+}
+
+string FSLib::canonical( const string &path ) {
+    char_t *full_path = new char_t[MAX_PATH];
+    char_t *canonical_path = new char_t[MAX_PATH];
+
+    auto failed = !GetFullPathName( path.c_str(), MAX_PATH, full_path, NULL );
+
+    if ( failed ) {
+        delete[] canonical_path;
+        delete[] full_path;
+        return string();
+    }
+
+    failed = !PathCanonicalizeW( canonical_path, full_path );
+
+    delete[] full_path;
+
+    if ( failed ) {
+        delete[] canonical_path;
+        return string();
+    }
+
+    string canonical_string{ canonical_path };
+    delete[] canonical_path;
+    return canonical_string;
+}
+
+bool FSLib::isDirectory( const string &path ) {
+    struct _stat path_stat;
+
+    if ( _wstat( path.c_str(), &path_stat ) != 0 )
+        return false;
+
+    return path_stat.st_mode & _S_IFDIR;
+}
+
+bool FSLib::rename( const string &file_a, const string &file_b ) {
+    return MoveFileExW( file_a.c_str(), file_b.c_str(),
+                        MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING );
+}
+
+bool FSLib::createDirectoryFull( const string &path ) {
+    uint64_t pos = path.find_first_of( L":", 0 ) + 2;
+    if ( pos == string::npos )
+        pos = 0;
+    // go through all directories leading to the last one
+    // and create them if they don't exist
+    do {
+        // get partial directory path
+        pos = path.find_first_of( L"\\", pos );
+        auto dirname = path.substr( 0, pos );
+        // create it if it doesn't exist
+        if ( !FSLib::exists( dirname ) ) {
+            if ( !CreateDirectoryW( dirname.c_str(), NULL ) )
+                return false;
+        }
+        pos++;
+    } while ( pos < path.length() && pos != 0 );
+    return true;
+}
+
+FSLib::Directory::iterator FSLib::Directory::end() {
+    return Iterator( true );
+}
+
+FSLib::Directory::const_iterator FSLib::Directory::end() const {
+    return Iterator( true );
+}
+
+char_t const *FSLib::Directory::Iterator::operator*() const {
+    return data.cFileName;
+}
+
+FSLib::Directory::Iterator &FSLib::Directory::Iterator::operator++() {
+    if ( ended == true )
+        return *this;
+    // skip . and ..
+    if ( FindNextFileW( hFind, &data ) == 0 ) {
+        ended = true;
+    } else if ( !wcscmp( data.cFileName, L"." ) ||
+                !wcscmp( data.cFileName, L".." ) ) {
+        return operator++();
+    }
+    return *this;
+}
+
+bool FSLib::Directory::Iterator::operator==( const Iterator &i_other ) const {
+    return i_other.ended == ended;
+}
+
+string FSLib::getContainingDirectory( const string &path ) {
+    auto pos = path.find_last_of('\\');
+    if(pos == string::npos) {
+        return ".";
+    }
+    return path.substr(0, pos);
+}
+
+string FSLib::getFileName( const string &path ) {
+    auto pos = path.find_last_of('\\');
+    if(pos == string::npos) {
+        return path;
+    }
+    return path.substr(pos+1);
+}
+
+string FSLib::getFileExtension( const string &path ) {
+    auto pos = path.find_last_of('.');
+    if(pos == string::npos) {
+        return "";
+    }
+    return path.substr(pos + 1);
+}