diff --git a/components/codetools/codetoolmanager.pas b/components/codetools/codetoolmanager.pas
index f67b46b2b6..e5450dfce8 100644
--- a/components/codetools/codetoolmanager.pas
+++ b/components/codetools/codetoolmanager.pas
@@ -214,6 +214,8 @@ type
     function GetCompiledSrcExtForDirectory(const Directory: string): string;
     function FindUnitInUnitLinks(const Directory, UnitName: string): string;
     function GetUnitLinksForDirectory(const Directory: string): string;
+    procedure GetFPCVersionForDirectory(const Directory: string;
+                                 var FPCVersion, FPCRelease, FPCPatch: integer);
 
     // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     
@@ -777,6 +779,55 @@ begin
   Result:=Evaluator[ExternalMacroStart+'UnitLinks'];
 end;
 
+procedure TCodeToolManager.GetFPCVersionForDirectory(const Directory: string;
+  var FPCVersion, FPCRelease, FPCPatch: integer);
+var
+  Evaluator: TExpressionEvaluator;
+  i: Integer;
+  VarName: String;
+  p: Integer;
+
+  function ReadInt(var AnInteger: integer): boolean;
+  var
+    StartPos: Integer;
+  begin
+    StartPos:=p;
+    AnInteger:=0;
+    while (p<=length(VarName)) and (VarName[p] in ['0'..'9']) do begin
+      AnInteger:=AnInteger*10+(ord(VarName[p])-ord('0'));
+      if AnInteger>=100 then begin
+        Result:=false;
+        exit;
+      end;
+      inc(p);
+    end;
+    Result:=StartPos<p;
+  end;
+  
+begin
+  FPCVersion:=0;
+  FPCRelease:=0;
+  FPCPatch:=0;
+  Evaluator:=DefineTree.GetDefinesForDirectory(Directory,true);
+  if Evaluator=nil then exit;
+  for i:=0 to Evaluator.Count-1 do begin
+    VarName:=Evaluator.Names(i);
+    if (length(VarName)>3) and (VarName[1] in ['V','v'])
+    and (VarName[2] in ['E','e']) and (VarName[3] in ['R','r'])
+    and (VarName[4] in ['0'..'9']) then begin
+      p:=4;
+      if not ReadInt(FPCVersion) then continue;
+      if (p>=length(VarName)) or (VarName[p]<>'_') then continue;
+      inc(p);
+      if not ReadInt(FPCRelease) then continue;
+      if (p>=length(VarName)) or (VarName[p]<>'_') then continue;
+      inc(p);
+      if not ReadInt(FPCPatch) then continue;
+      exit;
+    end;
+  end;
+end;
+
 function TCodeToolManager.Explore(Code: TCodeBuffer;
   var ACodeTool: TCodeTool; WithStatements: boolean): boolean;
 begin
diff --git a/components/codetools/expreval.pas b/components/codetools/expreval.pas
index 939e158b79..141fb31ac0 100644
--- a/components/codetools/expreval.pas
+++ b/components/codetools/expreval.pas
@@ -61,15 +61,15 @@ type
     function IndexOfName(const VarName: string): integer;
     procedure Expand;
   public
-    property Variables[const Name:string]: string
+    property Variables[const Name: string]: string
        read GetVariables write SetVariables;  default;
     property Count: integer read FCount;
-    procedure Undefine(const Name:string);
-    function IsDefined(const Name:string): boolean;
+    procedure Undefine(const Name: string);
+    function IsDefined(const Name: string): boolean;
     function Equals(AnExpressionEvaluator: TExpressionEvaluator): boolean;
     procedure Assign(SourceExpressionEvaluator: TExpressionEvaluator);
     procedure AssignTo(SL: TStringList);
-    function Eval(const Expression:string):string;
+    function Eval(const Expression: string):string;
     property ErrorPosition:integer read ErrorPos;
     property OnChange: TOnValuesChanged read FOnChange write FOnChange;
     function Items(Index: integer): string;
diff --git a/ide/buildlazdialog.pas b/ide/buildlazdialog.pas
index 5a80e7482c..bd41333a5a 100644
--- a/ide/buildlazdialog.pas
+++ b/ide/buildlazdialog.pas
@@ -133,7 +133,7 @@ type
     procedure Assign(Source: TBuildLazarusOptions);
     procedure SetBuildAll;
     function FindName(const Name: string): TBuildLazarusItem;
-    function CompiledUnitExt: string;
+    function CompiledUnitExt(FPCVersion, FPCRelease: integer): string;
   public
     property Count: integer read GetCount;
     property Items[Index: integer]: TBuildLazarusItem read GetItems;
@@ -207,7 +207,8 @@ function ShowConfigureBuildLazarusDlg(
 
 function BuildLazarus(Options: TBuildLazarusOptions;
   ExternalTools: TExternalToolList; Macros: TTransferMacroList;
-  const PackageOptions: string; Flags: TBuildLazarusFlags): TModalResult;
+  const PackageOptions, CompilerPath: string;
+  Flags: TBuildLazarusFlags): TModalResult;
 function CreateBuildLazarusOptions(Options: TBuildLazarusOptions;
   ItemIndex: integer; Macros: TTransferMacroList;
   const PackageOptions: string; Flags: TBuildLazarusFlags;
@@ -280,7 +281,8 @@ end;
 
 function BuildLazarus(Options: TBuildLazarusOptions;
   ExternalTools: TExternalToolList; Macros: TTransferMacroList;
-  const PackageOptions: string; Flags: TBuildLazarusFlags): TModalResult;
+  const PackageOptions, CompilerPath: string;
+  Flags: TBuildLazarusFlags): TModalResult;
 var
   Tool: TExternalToolOptions;
   i: Integer;
@@ -295,6 +297,8 @@ begin
     Tool.Filename:=Options.MakeFilename;
     Tool.EnvironmentOverrides.Values['LCL_PLATFORM']:=
       LCLPlatformNames[Options.LCLPlatform];
+    if CompilerPath<>'' then
+      Tool.EnvironmentOverrides.Values['PP']:=CompilerPath;
     if not FileExists(Tool.Filename) then begin
       Tool.Filename:=FindDefaultMakePath;
       if not FileExists(Tool.Filename) then exit;
@@ -1004,16 +1008,14 @@ begin
   end;
 end;
 
-function TBuildLazarusOptions.CompiledUnitExt: string;
+function TBuildLazarusOptions.CompiledUnitExt(FPCVersion, FPCRelease: integer
+  ): string;
 begin
-  Result:=GetDefaultCompiledUnitExt;
-  if AnsiCompareText(TargetOS,'win32')=0 then
+  Result:=GetDefaultCompiledUnitExt(FPCVersion,FPCRelease);
+  if (AnsiCompareText(TargetOS,'win32')=0)
+  and (FPCVersion=1) and (FPCRelease=0) then
     Result:='.ppw'
-  else if (AnsiCompareText(TargetOS,'linux')=0)
-  or (AnsiCompareText(TargetOS,'freebsd')=0)
-  or (AnsiCompareText(TargetOS,'netbsd')=0)
-  or (AnsiCompareText(TargetOS,'openbsd')=0)
-  then
+  else
     Result:='.ppu';
 end;
 
diff --git a/ide/include/unix/lazbaseconf.inc b/ide/include/unix/lazbaseconf.inc
index 9c796911a4..0bb2ebeede 100644
--- a/ide/include/unix/lazbaseconf.inc
+++ b/ide/include/unix/lazbaseconf.inc
@@ -154,7 +154,7 @@ begin
   Result:='';
 end;
 
-function GetDefaultCompiledUnitExt: string;
+function GetDefaultCompiledUnitExt(FPCVersion, FPCRelease: integer): string;
 begin
   Result:='.ppu';
 end;
diff --git a/ide/include/win32/lazconf.inc b/ide/include/win32/lazconf.inc
index 2cd6f18c82..905f5aab93 100644
--- a/ide/include/win32/lazconf.inc
+++ b/ide/include/win32/lazconf.inc
@@ -136,9 +136,12 @@ begin
   Result:='.exe';
 end;
 
-function GetDefaultCompiledUnitExt: string;
+function GetDefaultCompiledUnitExt(FPCVersion, FPCRelease: integer): string;
 begin
-  Result:='.ppw';
+  if (FPCVersion=1) and (FPCRelease=0) then
+    Result:='.ppw'
+  else
+    Result:='.ppu';
 end;
 
 function GetDefaultTestBuildDirectory: string;
@@ -179,6 +182,9 @@ end;
 
 {
   $Log$
+  Revision 1.18  2003/11/16 19:28:33  mattias
+  build lazarus now uses custom compiler path
+
   Revision 1.17  2003/11/15 13:07:09  mattias
   added ambigious unit check for IDE
 
diff --git a/ide/lazconf.pp b/ide/lazconf.pp
index 3b18abdd56..7a0332980f 100644
--- a/ide/lazconf.pp
+++ b/ide/lazconf.pp
@@ -80,7 +80,7 @@ uses
   function GetDefaultExecutableExt: string;
   
   // returns the standard file extension for compiled units (e.g '.ppu')
-  function GetDefaultCompiledUnitExt: string;
+  function GetDefaultCompiledUnitExt(FPCVersion, FPCRelease: integer): string;
 
   procedure GetDefaultCompilerFilenames(List: TStrings);
   procedure GetDefaultTestBuildDirs(List: TStrings);
@@ -143,6 +143,9 @@ end.
 
 {
   $Log$
+  Revision 1.21  2003/11/16 19:28:33  mattias
+  build lazarus now uses custom compiler path
+
   Revision 1.20  2003/11/15 13:07:09  mattias
   added ambigious unit check for IDE
 
diff --git a/ide/main.pp b/ide/main.pp
index 439616a27e..4e0b53df9f 100644
--- a/ide/main.pp
+++ b/ide/main.pp
@@ -5899,6 +5899,8 @@ var
   PkgOptions: string;
   IDEBuildFlags: TBuildLazarusFlags;
   InheritedOptionStrings: TInheritedCompOptsStrings;
+  CompiledUnitExt: String;
+  FPCVersion, FPCRelease, FPCPatch: integer;
 begin
   if ToolStatus<>itNone then begin
     MessageDlg(lisNotNow,
@@ -5913,7 +5915,8 @@ begin
     SourceNotebook.ClearErrorLines;
     Result:=BuildLazarus(MiscellaneousOptions.BuildLazOpts,
                          EnvironmentOptions.ExternalTools,MacroList,
-                         '',Flags+[blfWithoutLinkingIDE]);
+                         '',EnvironmentOptions.CompilerFilename,
+                         Flags+[blfWithoutLinkingIDE]);
     if Result<>mrOk then exit;
     
     // then compile the IDE
@@ -5936,10 +5939,15 @@ begin
       PkgOptions:=PkgBoss.DoGetIDEInstallPackageOptions(InheritedOptionStrings);
       
       // check ambigious units
+      CodeToolBoss.GetFPCVersionForDirectory(
+                                 EnvironmentOptions.LazarusDirectory,
+                                 FPCVersion,FPCRelease,FPCPatch);
+      CompiledUnitExt:=MiscellaneousOptions.BuildLazOpts.CompiledUnitExt(
+                         FPCVersion,FPCRelease);
       Result:=DoCheckUnitPathForAmbigiousPascalFiles(
                        EnvironmentOptions.LazarusDirectory,
                        InheritedOptionStrings[icoUnitPath],
-                       MiscellaneousOptions.BuildLazOpts.CompiledUnitExt,'IDE');
+                       CompiledUnitExt,'IDE');
       if Result<>mrOk then exit;
     end;
 
@@ -5953,7 +5961,8 @@ begin
     SourceNotebook.ClearErrorLines;
     Result:=BuildLazarus(MiscellaneousOptions.BuildLazOpts,
                          EnvironmentOptions.ExternalTools,MacroList,
-                         PkgOptions,IDEBuildFlags+[blfUseMakeIDECfg,blfDontClean]);
+                         PkgOptions,EnvironmentOptions.CompilerFilename,
+                         IDEBuildFlags+[blfUseMakeIDECfg,blfDontClean]);
     if Result<>mrOk then exit;
   finally
     DoCheckFilesOnDisk;
@@ -10091,6 +10100,9 @@ end.
 
 { =============================================================================
   $Log$
+  Revision 1.670  2003/11/16 19:28:33  mattias
+  build lazarus now uses custom compiler path
+
   Revision 1.669  2003/11/16 01:56:15  mattias
   changed TMenuItem.Graphic to TMenuItem.Bitmap