diff --git a/.gitignore b/.gitignore
index fa7060f..126820f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,7 +11,7 @@
 *.sublime-project
 *.sublime-workspace
 backup.*
-
+bld
 imgui.ini
 
 __pycache__/
diff --git a/build.bat b/build.bat
index 5b8e34d..74c0d38 100644
--- a/build.bat
+++ b/build.bat
@@ -3,7 +3,7 @@ call ../misc/compile_setup.bat
 
 mkdir build
 cd build
-cl -Fe:bld.exe ../bld_main.cpp -WX -W3 -wd4200 -diagnostics:column -nologo -Zi -D_CRT_SECURE_NO_WARNINGS /MD
+cl -Fe:bld.exe ../build_main.cpp -WX -W3 -wd4200 -diagnostics:column -nologo -Zi -D_CRT_SECURE_NO_WARNINGS /MD
 cd ..
 build\bld.exe
 
diff --git a/build.sh b/build.sh
index b626afa..a640b25 100644
--- a/build.sh
+++ b/build.sh
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
-gcc -o bld bld_main.cpp -g
+gcc -o bld build_main.cpp -g
 ./bld
diff --git a/bld_file.cpp b/build_file.cpp
similarity index 88%
rename from bld_file.cpp
rename to build_file.cpp
index eb92b87..eac76c5 100644
--- a/bld_file.cpp
+++ b/build_file.cpp
@@ -1,4 +1,4 @@
-#include "bld_lib.cpp"
+#include "build_lib.cpp"
 
 Strs cc = ON_WINDOWS("cl") ON_MAC("clang") ON_LINUX("gcc");
 
@@ -15,6 +15,7 @@ int CompileFiles(Strs files) {
     else {
         result = OS_SystemF("cl -Fe:%Q.exe %Q -Zi -WX -W3 -wd4200 -diagnostics:column -nologo -D_CRT_SECURE_NO_WARNINGS", exe, filestr);
     }
+    if (result == 0) result = OS_SystemF(IF_WINDOWS_ELSE("", "./") "%Q.exe", exe);
     return result;
 }
 
diff --git a/bld_lib.cpp b/build_lib.cpp
similarity index 81%
rename from bld_lib.cpp
rename to build_lib.cpp
index e84de03..9730e4b 100644
--- a/bld_lib.cpp
+++ b/build_lib.cpp
@@ -1,3 +1,30 @@
+/*
+----------------- CL.EXE -----------------
+FLAGS        = /MP /Zi /FC /WX /W3 /wd4200 /diagnostics:column /nologo -D_CRT_SECURE_NO_WARNINGS /GF /Gm- /Oi
+LINK         = /link /incremental:no
+STD_OFF      = /GR- /EHa-
+STD_ON       = /EHsc
+DEBUG        = -Od -D_DEBUG -MDd -fsanitize=address -RTC1
+DEBUG_LINK   = -NODEFAULTLIB:LIBCMT
+RELEASE      = -O2 -MT -DNDEBUG -GL
+RELEASE_LINK = -opt:ref -opt:icf
+----------------- CL.EXE -----------------
+/FC      = Print full paths in diagnostics
+/Gm-     = Old feature, 'minimal compilation', in case it's not off by default
+/GF      = Pools strings as read-only. If you try to modify strings under /GF, an application error occurs.
+/Oi      = Replaces some function calls with intrinsic
+/MP      = Multithreaded compilation
+/GR-     = Disable runtime type information
+/EHa-    = Disable exceptions
+/EHsc    = Enable exceptions
+/MT      = Link static libc. The 'd' means debug version
+/MD      = Link dynamic libc. The 'd' means debug version
+/GL      = Whole program optimization
+/RTC1    = runtime error checks
+/opt:ref = eliminates functions and data that are never referenced
+/opt:icf = eliminates redundant 'COMDAT's
+*/
+
 #ifndef _CRT_SECURE_NO_WARNINGS
 #define _CRT_SECURE_NO_WARNINGS
 #endif
@@ -294,49 +321,10 @@ Strs ListDir(char *dir) {
     return result;
 }
 
-void PrintCompilerFlagHelp(Strs cc) {
-    if (cc == "cl") {
-        IO_Printf("------- CL.EXE -------\n");
-        IO_Printf("/FC   = Print full paths in diagnostics\n");
-        IO_Printf("/Gm-  = Old feature, 'minimal compilation', in case it's not off by default\n");
-        IO_Printf("/GF   = Pools strings as read-only. If you try to modify strings under /GF, an application error occurs.\n");
-        IO_Printf("/Oi   = Replaces some function calls with intrinsic \n");
-        IO_Printf("/MP   = Multithreaded compilation\n");
-
-        IO_Printf("/GR-  = Disable runtime type information\n");
-        IO_Printf("/EHa- = Disable exceptions\n");
-        IO_Printf("/EHsc = Enable exceptions\n");
-
-        IO_Printf("/MT = Link static libc. The 'd' means debug version \n");
-        IO_Printf("/MD = Link dynamic libc. The 'd' means debug version\n");
-        IO_Printf("/GL = Whole program optimization \n");
-        IO_Printf("/RTC1 = runtime error checks \n");
-        IO_Printf("/opt:ref = eliminates functions and data that are never referenced\n");
-        IO_Printf("/opt:icf = eliminates redundant 'COMDAT's\n");
-
-        IO_Printf("----------------------\n");
-        IO_Printf("FLAGS   = /MP /Zi /FC /WX /W3 /wd4200 /diagnostics:column /nologo -D_CRT_SECURE_NO_WARNINGS /GF /Gm- /Oi\n");
-        IO_Printf("LINK    = /link /incremental:no\n");
-        IO_Printf("STD_OFF = /GR- /EHa-\n");
-        IO_Printf("STD_ON  = /EHsc\n");
-        IO_Printf("DEBUG   = -Od -D_DEBUG -MDd -fsanitize=address -RTC1\n");
-        // IO_Printf("LINK  = -NODEFAULTLIB:LIBCMT\n");
-        IO_Printf("RELEASE = -O2 -MT -DNDEBUG -GL\n");
-        IO_Printf("LINK    = -opt:ref -opt:icf\n");
-    }
-    else if (cc == "gcc") {
-    }
-    else if (cc == "clang") {
-    }
-    else {
-        IO_FatalErrorf("Unhandled compiler");
-    }
-}
-
-#ifndef BLD_MAIN
+#ifndef BUILD_MAIN
 int Main();
 int main() {
-    SRC_InitCache(Perm, S8_Lit("bld_file.cache"));
+    SRC_InitCache(Perm, S8_Lit("build_file.cache"));
     int result = Main();
     if (result == 0) SRC_SaveCache();
 }
diff --git a/bld_main.cpp b/build_main.cpp
similarity index 90%
rename from bld_main.cpp
rename to build_main.cpp
index ba51ba7..76c1da3 100644
--- a/bld_main.cpp
+++ b/build_main.cpp
@@ -1,5 +1,5 @@
-#define BLD_MAIN
-#include "bld_lib.cpp"
+#define BUILD_MAIN
+#include "build_lib.cpp"
 
 int main(int argument_count, char **arguments) {
     OS_MakeDir(S8_Lit("build"));
@@ -10,17 +10,17 @@ int main(int argument_count, char **arguments) {
 
     for (int i = 1; i < argument_count; i += 1) {
         S8_String arg = S8_MakeFromChar(arguments[i]);
-        if (arg == "clear_cache"_s) OS_DeleteFile("bld_tool.cache"_s);
+        if (arg == "clear_cache"_s) OS_DeleteFile("build_tool.cache"_s);
     }
 
-    SRC_InitCache(Perm, S8_Lit("bld.cache"));
+    SRC_InitCache(Perm, S8_Lit("build_tool.cache"));
 
     // Search for build file in the project directory
     S8_String build_file = {0};
     {
         S8_List files_current_dir = OS_ListDir(Perm, S8_Lit(".."), 0);
         for (S8_Node *it = files_current_dir.first; it; it = it->next) {
-            if (S8_Find(it->string, S8_Lit("bld_file.c"), S8_IGNORE_CASE, 0)) {
+            if (S8_Find(it->string, S8_Lit("build_file.c"), S8_IGNORE_CASE, 0)) {
                 build_file = it->string;
             }
         }
diff --git a/filesystem.c b/filesystem.c
index c5a1d65..7ec9c2e 100644
--- a/filesystem.c
+++ b/filesystem.c
@@ -290,21 +290,20 @@ static OS_Result OS__WriteFile(S8_String path, S8_String data, bool append) {
         IO_Assert(data.len == (DWORD)data.len); // @Todo: can only read 32 byte size files?
         BOOL error = WriteFile(handle, data.str, (DWORD)data.len, &bytes_written, NULL);
         if (error == TRUE) {
-            if (bytes_written != data.len) {
+            if (bytes_written == data.len) {
                 result = OS_SUCCESS;
             }
         }
         CloseHandle(handle);
     }
-    else
-        result = OS_PATH_NOT_FOUND;
+    else result = OS_PATH_NOT_FOUND;
 
     return result;
 }
 
 OS_API OS_Result OS_AppendFile(S8_String path, S8_String string) {
     return OS__WriteFile(path, string, true);
-} // @untested
+}
 
 OS_API OS_Result OS_WriteFile(S8_String path, S8_String string) {
     return OS__WriteFile(path, string, false);
diff --git a/filesystem.h b/filesystem.h
index c8cd23f..08aa283 100644
--- a/filesystem.h
+++ b/filesystem.h
@@ -1,4 +1,5 @@
 #pragma once
+// Quick and dirty filesystem operations
 
 #ifndef OS_API
     #ifdef __cplusplus