This folder contains the installer for the 64 bit version of Lazarus 1.2.4. This installation is only for 64 bit versions of Windows.
* The Lazarus team recommends to use the 32bit Version of Lazarus, even for working on 64bit platforms, or for generating 64 bit applications. 
* The 64 bit only installer is:
You should download this file, if you want to work only on Windows 64 bit versions.
The installer includes FPC 2.6.4 and it includes the Lazarus help files.
* Add-On for building and debugging 32bit Windows applications:
This file can be installed as add-on to the 64 bit Lazarus IDE (on Systems with Windows 64 bit only), if you wish to develop for 32bit Windows too.
For an overview what changed since the 1.2 Release see:
For an overview what changed from 1.0 and 1.0x Versions (includes incompatibilities with earlier versions) see:
For additional information visit our homepage, forum, wiki, and FAQ:
Current released versions of FPC (2.6.x) do not include support for SEH handling. This can affect the stability of many 64 bit applications. Therefore it is recommended to use the 32bit IDE, and generate 32bit applications only. This will change when FPC 2.8.0 is released.
Please visit our forums and Wiki for additional information.
Source: WARNING This build has serious stability issues - See README.txt, updated 2014-06-15