diff --git a/ide/checkcompileropts.pas b/ide/checkcompileropts.pas
index aab34b766b..4f41b1dea4 100644
--- a/ide/checkcompileropts.pas
+++ b/ide/checkcompileropts.pas
@@ -700,7 +700,7 @@ var
   var
     CurDate: LongInt;
   begin
-    CurDate:=FileAgeUTF8(aFilename);
+    CurDate:=FileAgeCached(aFilename);
     //DebugLn(['CheckFileAge ',aFilename,' ',CurDate]);
     if (CurDate=-1) then exit;
     if (MinPPUDate=-1) or (MinPPUDate>CurDate) then begin
@@ -731,7 +731,7 @@ begin
 
   Result:=mrCancel;
   
-  CompilerDate:=FileAgeUTF8(CompilerFilename);
+  CompilerDate:=FileAgeCached(CompilerFilename);
   if CompilerDate=-1 then begin
     Result:=MessageDlg(lisCCOErrorCaption,Format(lisCCOUnableToGetFileDate,[CompilerFilename]),
       mtError,[mbIgnore,mbAbort],0);
diff --git a/ide/environmentopts.pp b/ide/environmentopts.pp
index 5e569c4905..5186e2ec92 100644
--- a/ide/environmentopts.pp
+++ b/ide/environmentopts.pp
@@ -34,7 +34,7 @@ uses
 {$IFDEF IDE_MEM_CHECK}
   MemCheck,
 {$ENDIF}
-  Classes, SysUtils, Graphics, Controls, Forms, LCLProc, FileUtil, Dialogs,
+  Classes, SysUtils, Graphics, Controls, Forms, LCLProc, FileProcs, Dialogs,
   Laz_XMLCfg, AvgLvlTree, ProjectIntf,
   IDEProcs, LazarusIDEStrConsts, IDETranslations, LazConf,
   ObjectInspector, IDEOptionDefs, IDEWindowIntf, ExtToolDialog, TransferMacros,
@@ -1488,7 +1488,7 @@ end;
 function TEnvironmentOptions.FileHasChangedOnDisk: boolean;
 begin
   Result:=FFileHasChangedOnDisk
-      or ((FFilename<>'') and (FFileAge<>0) and (FileAgeUTF8(FFilename)<>FFileAge));
+      or ((FFilename<>'') and (FFileAge<>0) and (FileAgeCached(FFilename)<>FFileAge));
   FFileHasChangedOnDisk:=Result;
 end;
 
@@ -1512,7 +1512,7 @@ procedure TEnvironmentOptions.FileUpdated;
 begin
   FFileHasChangedOnDisk:=false;
   if FFilename<>'' then
-    FFileAge:=FileAgeUTF8(FFilename)
+    FFileAge:=FileAgeCached(FFilename)
   else
     FFileAge:=0;
 end;
diff --git a/ide/idetranslations.pas b/ide/idetranslations.pas
index ce3dfb96b6..82d1883045 100644
--- a/ide/idetranslations.pas
+++ b/ide/idetranslations.pas
@@ -31,7 +31,7 @@ interface
 
 uses
   Classes, SysUtils, GetText, LCLProc, Translations,
-  IDEProcs, FileUtil,
+  IDEProcs, FileProcs,
   avl_tree, LazarusIDEStrConsts;
   { IDE Language (Human, not computer) }
 
@@ -224,7 +224,7 @@ begin
 
       //DebugLn(['ConvertPackageRSTFiles RSTFilename=',RSTFilename,' OutputFilename=',OutputFilename]);
       if (not FileExistsUTF8(OutputFilename))
-      or (FileAgeUTF8(RSTFilename)>FileAgeUTF8(OutputFilename)) then
+      or (FileAgeCached(RSTFilename)>FileAgeCached(OutputFilename)) then
       begin
         FileList.Add(RSTFilename);
         {$ifndef SinglePOFile}
diff --git a/ide/inputhistory.pas b/ide/inputhistory.pas
index 4af287d5e3..8583dede50 100644
--- a/ide/inputhistory.pas
+++ b/ide/inputhistory.pas
@@ -35,7 +35,7 @@ unit InputHistory;
 interface
 
 uses
-  Classes, SysUtils, FileUtil, DiffPatch, IDEProcs, AvgLvlTree,
+  Classes, SysUtils, FileUtil, FileProcs, DiffPatch, IDEProcs, AvgLvlTree,
   SynEditTypes, Laz_XMLCfg, LazConf, Dialogs, LCLProc;
 
 {$ifdef Windows}
@@ -851,8 +851,8 @@ begin
   Clear;
   FCompilerPath:=AValue;
   ResolvedFilename:=ReadAllLinks(FCompilerPath,false);
-  if FileExistsUTF8(ResolvedFilename) then
-    FCompilerAge:=FileAgeUTF8(ResolvedFilename)
+  if FileExistsCached(ResolvedFilename) then
+    FCompilerAge:=FileAgeCached(ResolvedFilename)
   else
     FCompilerAge:=-1;
 end;
@@ -947,7 +947,7 @@ begin
   if Result and CheckCompiler then begin
     ResolvedFilename:=ReadAllLinks(FCompilerPath,false);
     if FileExistsUTF8(ResolvedFilename)
-    and (FileAgeUTF8(ResolvedFilename)=FCompilerAge) then
+    and (FileAgeCached(ResolvedFilename)=FCompilerAge) then
       exit;
     FCompilerAge:=-1;
     Result:=false;
diff --git a/ide/main.pp b/ide/main.pp
index 0d3ab27448..45b62d00f5 100644
--- a/ide/main.pp
+++ b/ide/main.pp
@@ -59,13 +59,13 @@ uses
   MemCheck,
 {$ENDIF}
   // fpc packages
-  Math, Classes, SysUtils, Process, AsyncProcess, TypInfo,
+  Math, Classes, SysUtils, Process, AsyncProcess, TypInfo, AVL_Tree,
   // lcl
   LCLProc, LCLMemManager, LCLType, LCLIntf, LConvEncoding, LMessages, ComCtrls,
-  LResources, StdCtrls, Forms, Buttons, Menus, FileUtil, Controls, GraphType,
+  FileUtil, LResources, StdCtrls, Forms, Buttons, Menus, Controls, GraphType,
   HelpIntfs, Graphics, ExtCtrls, Dialogs, InterfaceBase, LDockCtrl, UTF8Process,
   // codetools
-  CodeBeautifier, FindDeclarationTool, LinkScanner, BasicCodeTools, AVL_Tree,
+  FileProcs, CodeBeautifier, FindDeclarationTool, LinkScanner, BasicCodeTools,
   Laz_XMLCfg, CodeToolsStructs, CodeToolManager, CodeCache, DefineTemplates,
   // synedit
   SynEditKeyCmds, SynBeautifier, SynEditMarks,
@@ -3648,7 +3648,7 @@ begin
                           +lisAllFiles+'|'+GetAllFilesMask;
       if OpenDialog.Execute then begin
         AFilename:=ExpandFileNameUTF8(OpenDialog.Filename);
-        if CompareFileExt(AFilename,'.lpi')<>0 then begin
+        if FileUtil.CompareFileExt(AFilename,'.lpi')<>0 then begin
           // not a lpi file
           // check if it is a program source
 
@@ -3828,7 +3828,7 @@ begin
 
   POFileAgeValid:=false;
   if FileExistsCached(POFilename) then begin
-    POFileAge:=FileAgeUTF8(POFilename);
+    POFileAge:=FileAgeCached(POFilename);
     POFileAgeValid:=true;
   end;
 
@@ -3844,7 +3844,7 @@ begin
         // check .lst file
         LRTFilename:=ChangeFileExt(CurFilename,'.lrt');
         if FileExistsCached(LRTFilename)
-        and ((not POFileAgeValid) or (FileAgeUTF8(LRTFilename)>POFileAge)) then
+        and ((not POFileAgeValid) or (FileAgeCached(LRTFilename)>POFileAge)) then
           Files.Add(LRTFilename);
         // check .rst file
         RSTFilename:=ExtractFileName(ChangeFileExt(CurFilename,'.rst'));
@@ -3859,7 +3859,7 @@ begin
         //DebugLn(['TMainIDE.UpdateProjectPOFile Looking for .rst file ="',RSTFilename,'"']);
 
         if FileExistsCached(RSTFilename)
-        and ((not POFileAgeValid) or (FileAgeUTF8(RSTFilename)>POFileAge)) then
+        and ((not POFileAgeValid) or (FileAgeCached(RSTFilename)>POFileAge)) then
           Files.Add(RSTFilename);
       end;
       AnUnitInfo:=AnUnitInfo.NextPartOfProject;
@@ -9548,7 +9548,8 @@ begin
     Ext:='.lpi';
   end;
 
-  if (not FileIsText(AFilename,FileReadable)) and FileReadable then begin
+  if (not FileUtil.FileIsText(AFilename,FileReadable)) and FileReadable then
+  begin
     ACaption:=lisFileNotText;
     AText:=Format(lisFileDoesNotLookLikeATextFileOpenItAnyway, ['"', AFilename,
       '"', #13, #13]);
@@ -10113,7 +10114,7 @@ begin
   or (AProject.LastCompilerParams<>CompilerParams)
   or ((AProject.LastCompilerFileDate>0)
       and FileExistsCached(CompilerFilename)
-      and (FileAgeUTF8(CompilerFilename)<>AProject.LastCompilerFileDate))
+      and (FileAgeCached(CompilerFilename)<>AProject.LastCompilerFileDate))
   then
     NeedBuildAllFlag:=true;
 
@@ -10126,10 +10127,10 @@ begin
     exit(mrYes);
   end;
 
-  StateFileAge:=FileAgeUTF8(StateFilename);
+  StateFileAge:=FileAgeCached(StateFilename);
 
   // check main source file
-  if FileExistsUTF8(SrcFilename) and (StateFileAge<FileAgeUTF8(SrcFilename)) then
+  if FileExistsCached(SrcFilename) and (StateFileAge<FileAgeCached(SrcFilename)) then
   begin
     DebugLn('TMainIDE.CheckIfProjectNeedsCompilation  SrcFile outdated ',AProject.IDAsString);
     exit(mrYes);
@@ -10147,7 +10148,7 @@ begin
     DebugLn('  File="',CompilerFilename,'"');
     exit(mrYes);
   end;
-  if FileAgeUTF8(CompilerFilename)<>AProject.LastCompilerFileDate then begin
+  if FileAgeCached(CompilerFilename)<>AProject.LastCompilerFileDate then begin
     DebugLn('TMainIDE.CheckIfProjectNeedsCompilation  Compiler file changed for ',AProject.IDAsString);
     DebugLn('  File="',CompilerFilename,'"');
     exit(mrYes);
@@ -10171,8 +10172,8 @@ begin
   // check project files
   AnUnitInfo:=AProject.FirstPartOfProject;
   while AnUnitInfo<>nil do begin
-    if FileExistsUTF8(AnUnitInfo.Filename)
-    and (StateFileAge<FileAgeUTF8(AnUnitInfo.Filename)) then begin
+    if FileExistsCached(AnUnitInfo.Filename)
+    and (StateFileAge<FileAgeCached(AnUnitInfo.Filename)) then begin
       DebugLn('TMainIDE.CheckIfProjectNeedsCompilation  Src has changed ',AProject.IDAsString,' ',AnUnitInfo.Filename);
       exit(mrYes);
     end;
@@ -10183,8 +10184,8 @@ begin
   AnUnitInfo:=AProject.FirstUnitWithEditorIndex;
   while AnUnitInfo<>nil do begin
     if (not AnUnitInfo.IsPartOfProject)
-    and FileExistsUTF8(AnUnitInfo.Filename)
-    and (StateFileAge<FileAgeUTF8(AnUnitInfo.Filename)) then begin
+    and FileExistsCached(AnUnitInfo.Filename)
+    and (StateFileAge<FileAgeCached(AnUnitInfo.Filename)) then begin
       DebugLn('TMainIDE.CheckIfProjectNeedsCompilation  Editor Src has changed ',AProject.IDAsString,' ',AnUnitInfo.Filename);
       exit(mrYes);
     end;
@@ -10524,7 +10525,7 @@ begin
           // save state, so that next time the project is not compiled clean
           Project1.LastCompilerFilename:=CompilerFilename;
           Project1.LastCompilerParams:=CompilerParams;
-          Project1.LastCompilerFileDate:=FileAgeUTF8(CompilerFilename);
+          Project1.LastCompilerFileDate:=FileAgeCached(CompilerFilename);
           DoJumpToCompilerMessage(-1,true);
           CompileProgress.Ready(lisInfoBuildError);
           exit;
@@ -12568,7 +12569,7 @@ var
 
     SearchFile:=AFilename;
     SearchPath:=AllIncPaths;
-    Result:=SearchFileInPath(SearchFile,BaseDir,SearchPath,';',[]);
+    Result:=FileUtil.SearchFileInPath(SearchFile,BaseDir,SearchPath,';',[]);
     {$IFDEF VerboseFindSourceFile}
     debugln(['TMainIDE.SearchIndirectIncludeFile Result="',Result,'"']);
     {$ENDIF}
@@ -12583,7 +12584,7 @@ var
     Filename:='';
     SearchPath:=RemoveSearchPaths(TheSearchPath,AlreadySearchedPaths);
     if SearchPath<>'' then begin
-      Filename:=SearchFileInPath(SearchFile,BaseDir,SearchPath,';',[]);
+      Filename:=FileUtil.SearchFileInPath(SearchFile,BaseDir,SearchPath,';',[]);
       {$IFDEF VerboseFindSourceFile}
       debugln(['TMainIDE.FindSourceFile trying "',SearchPath,'" Filename="',Filename,'"']);
       {$ENDIF}
diff --git a/ide/project.pp b/ide/project.pp
index 5fd129b236..64ca3996e2 100644
--- a/ide/project.pp
+++ b/ide/project.pp
@@ -49,8 +49,10 @@ uses
   MemCheck,
 {$ENDIF}
   Classes, SysUtils, TypInfo, FPCAdds, LCLProc, LCLIntf, LCLType, Forms,
-  Controls, Dialogs, InterfaceBase,
-  Laz_XMLCfg, ExprEval, FileUtil, DefineTemplates, CodeToolManager, CodeCache, ProjectIntf, MacroIntf, LazIDEIntf,
+  FileUtil, Controls, Dialogs, InterfaceBase,
+  Laz_XMLCfg, ExprEval, FileProcs, DefineTemplates, CodeToolManager, CodeCache,
+  // IDEIntf
+  ProjectIntf, MacroIntf, LazIDEIntf,
   // IDE
   CompOptsModes, ProjectResources, LazConf, frmCustomApplicationOptions,
   LazarusIDEStrConsts, CompilerOptions,
@@ -2631,7 +2633,7 @@ begin
     if CompareFilenames(ProjectInfoFile,xmlconfig.Filename)=0 then begin
       fProjectInfoFileBuffer:=CodeToolBoss.LoadFile(ProjectInfoFile,true,true);
       try
-        fProjectInfoFileDate:=FileAgeUTF8(ProjectInfoFile);
+        fProjectInfoFileDate:=FileAgeCached(ProjectInfoFile);
       except
       end;
     end;
@@ -2965,7 +2967,7 @@ begin
     ProjectInfoFile:=NewProjectInfoFile;
     fProjectInfoFileBuffer:=CodeToolBoss.LoadFile(ProjectInfoFile,true,true);
     try
-      fProjectInfoFileDate:=FileAgeUTF8(ProjectInfoFile);
+      fProjectInfoFileDate:=FileAgeCached(ProjectInfoFile);
       {$IFDEF IDE_MEM_CHECK}CheckHeapWrtMemCnt('TProject.ReadProject A reading lpi');{$ENDIF}
       if fProjectInfoFileBuffer=nil then
         xmlconfig := TXMLConfig.CreateClean(ProjectInfoFile)
@@ -4052,7 +4054,7 @@ begin
   end;
 
   if not FileExistsCached(ProjectInfoFile) then exit;
-  if fProjectInfoFileDate=FileAgeUTF8(ProjectInfoFile) then exit;
+  if fProjectInfoFileDate=FileAgeCached(ProjectInfoFile) then exit;
 
   //DebugLn(['TProject.HasProjectInfoFileChangedOnDisk ',ProjectInfoFile,' fProjectInfoFileDate=',fProjectInfoFileDate,' ',FileAgeUTF8(ProjectInfoFile)]);
   Result:=true;
@@ -4060,7 +4062,7 @@ end;
 
 procedure TProject.IgnoreProjectInfoFileOnDisk;
 begin
-  fProjectInfoFileDate:=FileAgeUTF8(ProjectInfoFile);
+  fProjectInfoFileDate:=FileAgeCached(ProjectInfoFile);
 end;
 
 function TProject.FindDependencyByName(const PackageName: string
@@ -4550,7 +4552,7 @@ begin
   end;
 
   // read the state file
-  CurStateFileAge:=FileAgeUTF8(StateFile);
+  CurStateFileAge:=FileAgeCached(StateFile);
   if (not (lpsfStateFileLoaded in StateFlags))
   or (StateFileDate<>CurStateFileAge) then
   begin
@@ -4593,7 +4595,7 @@ var
 begin
   StateFile:=GetStateFilename;
   try
-    CompilerFileDate:=FileAgeUTF8(CompilerFilename);
+    CompilerFileDate:=FileAgeCached(CompilerFilename);
     XMLConfig:=TXMLConfig.CreateClean(StateFile);
     try
       XMLConfig.SetValue('Compiler/Value',CompilerFilename);
@@ -4607,7 +4609,7 @@ begin
     LastCompilerFilename:=CompilerFilename;
     LastCompilerFileDate:=CompilerFileDate;
     LastCompilerParams:=CompilerParams;
-    StateFileDate:=FileAgeUTF8(StateFile);
+    StateFileDate:=FileAgeCached(StateFile);
     StateFlags:=StateFlags+[lpsfStateFileLoaded];
   except
     on E: Exception do begin