Change the Login Screen Wallpaper in OS X Mavericks
Changing the login screens background wallpaper is a great way to customize the appearance of a Mac. The process of doing so seems to change with every release of OS X though, and that’s no different with swapping out the login wallpaper in OS X Mavericks. Changed yet again with OS X 10.9, you will find that rather than replacing a single file with a new image, you’ll have to replace four separate files to gain a similar customization of the login window, which is seen both upon system boot and with swapping logins with Fast User Switching.



Dictation is the new speech-to-text engine that lets your Mac type out what you are saying as you talk, and it’s one of the many excellent features included with modern versions of Mac OS X. Now from Mavericks onward, you can improve Dictation considerably by enabling an option called “Enhanced Dictation”, this will provide two significant advancements; continuous dictation with live feedback as you talk, and full offline support – meaning you won’t need a Mac to be connected to the internet in order to use the feature. 
Already installed OS X Mavericks, but now you want to
Java has plenty of real-world applications and uses, but because it has been used as an attack vector in the past, Apple has made OS X reasonably aggressive in limiting Java on Macs. As a result, Mavericks does not come with Java preinstalled, and upgraded Macs will remove Java in Mavericks installation process. For most users this is a very good thing, it further reduces the unlikely event of a trojan or something nefarious being installed on Macs, and many Mac users won’t notice Java missing at all. On the other hand, many of us do need Java installed in OS X.
Network Utility is a great tool that has been around on the Mac since the very first version of Mac OS X. It provides a variety of helpful networking tools and details, the “Info” tab includes general network info on a per interface level showingIP address, MAC address, link speeds, and sent/received data transfer statistics, and you’ll also have easy GUI access to what are otherwise command line tools, like 
Sharing files between Macs and NAS drives and Windows PC’s has always been very easy, but Mavericks brought a slight change that has caused some problems for certain users in mixed PC and Mac environments. Without getting too geeky, Apple adjusted the default protocol for SMB (Samba, the Windows file sharing ability) from SMB1 to SMB2, and the SMB2 implementation apparently carries a bug which is incompatible with many NAS (Network Attached Storage) devices, and some versions of Windows. The issue is pretty obvious when you encounter it: Many Windows PC’s, NAS drives, and Linux machines won’t access or mount from the Mac, and instead will try to connect or mount forever and ultimately time out, preventing connections,
App Nap is a great feature that arrived with OS X Mavericks which automatically pauses applications once they have gone unused for a period of time, helping to reduce energy consumption and saving battery life for portable Macs. Though App Nap can make a big difference in extending the battery life of MacBooks, there are some unique situations where users may not want an application to pause itself when unused, inactive, or otherwise in the background. For these situations, you can selectively prevent App Nap by disabling it on a per-application basis. Most users should not disable App Nap without a compelling reason to do so.
All of the latest versions of OS X have opted for a conservative approach to showing the users ~/Library/ directory, a folder which contains a variety of important files, settings, preferences, caches, and many specific files that are required for apps to run as intended. Because of the possibility of unintentional harm to a users Mac, OS X defaults to hiding that folder, with the intention on preventing novice users from making changes to it. OS X Mavericks is no different, but with the release of 10.9, all Mac users have an easy option to permanently show the User Library directory without having to result to the command line or other tricks that were previously required for access to the ~/Library folder.





