Q: iMac running low on RAM

My iMac (2008) is currently munching up RAM like a toddler in a candy shop. As I type I only have Safari open and it is showing between 10-16MB of RAM available. I have run Etre Check which has given me a full report but I have absolutely no idea what I'm meant to be looking for or how I'm meant to resolve it. I'm hoping there is a good Samaritan out there who is able to point me in the right direction. In general my machine works well and I have just cleaned up the hard drive where there were some link errors but I can't understand where all my RAM is going?

Here are the Etrecheck results:

EtreCheck version: 1.9.15 (52)

Report generated 18 September 2014 12:33:03 BST

Hardware Information: ?

  iMac (20-inch, Early 2008) (Verified)

  iMac - model: iMac8,1

  1 2.66 GHz Intel Core 2 Duo CPU: 2 cores

  4 GB RAM

Video Information: ?

  ATI Radeon HD 2600 Pro - VRAM: 256 MB

  iMac 1680 x 1050

System Software: ?

  OS X 10.9.4 (13E28) - Uptime: 0 days 0:48:16

Disk Information: ?

  ST3500418ASQ disk0 : (500.11 GB)

  S.M.A.R.T. Status: Verified

  EFI (disk0s1) <not mounted>: 209.7 MB

  Macintosh HD (disk0s2) / [Startup]: 406.3 GB (7.25 GB free) (Low!)

  Recovery HD (disk0s3) <not mounted>: 650 MB

  Untitled (disk0s4) /Volumes/Untitled: 92.95 GB (44.55 GB free)

USB Information: ?

  PIXART USB OPTICAL MOUSE

  Microsoft Comfort Curve Keyboard 3000

  SanDisk Cruzer Blade 16.01 GB

  S.M.A.R.T. Status: Verified

  ACS CRUSER (disk1s1) /Volumes/ACS CRUSER: 16.01 GB (14.27 GB free)

  Apple Inc. Built-in iSight

  Western Digital Elements 10B8 2 TB

  S.M.A.R.T. Status: Verified

  EFI (disk2s1) <not mounted>: 209.7 MB

  WD ADRIAN (disk2s2) /Volumes/WD ADRIAN: 2 TB (1.54 TB free)

  Apple Inc. BRCM2046 Hub

  Apple Inc. Bluetooth USB Host Controller

  Apple Computer, Inc. IR Receiver

Configuration files: ?

  /etc/sysctl.conf - Exists

Gatekeeper: ?

  Mac App Store and identified developers

Kernel Extensions: ?

  [not loaded] com.freecom.driver.BoulderScsi (1.0.0d1) Support

  [not loaded] com.paceap.kext.pacesupport.leopard (5.7.2) Support

  [not loaded] com.paceap.kext.pacesupport.master (5.7.2) Support

  [not loaded] com.paceap.kext.pacesupport.panther (5.7.2) Support

  [loaded] com.paceap.kext.pacesupport.snowleopard (5.7.2) Support

  [not loaded] com.paceap.kext.pacesupport.tiger (5.7.2) Support

  [not loaded] com.wacom.kext.pentablet (5.0.8) Support

Startup Items: ?

  PACESupport: Path: /Library/StartupItems/PACESupport

Launch Daemons: ?

  [loaded] com.adobe.fpsaud.plist Support

  [loaded] com.adobe.versioncueCS4.plist Support

  [running] com.edb.launchd.postgresql-8.4.plist Support

  [loaded] com.microsoft.office.licensing.helper.plist Support

  [loaded] PACESupport.plist Support

Launch Agents: ?

  [not loaded] com.adobe.AAM.Updater-1.0.plist Support

  [loaded] com.adobe.CS4ServiceManager.plist Support

  [loaded] com.hp.help.tocgenerator.plist Support

  [running] com.wacom.pentablet.plist Support

User Launch Agents: ?

  [loaded] com.adobe.ARM.[...].plist Support

  [failed] com.apple.CSConfigDotMacCert-@me.com-SharedServices.Agent.plist

  [loaded] com.divx.agent.postinstall.plist Support

  [failed] com.zeobit.MacKeeper.Helper.plist Support

User Login Items: ?

  AdobeResourceSynchronizer

  Dropbox

  HPEventHandler

Internet Plug-ins: ?

  OVSHelper: Version: 1.1 Support

  Default Browser: Version: 537 - SDK 10.9

  Flip4Mac WMV Plugin: Version: 2.4.4.2 Support

  Unity Web Player: Version: UnityPlayer version 3.5.5f2 - SDK 10.6 Support

  AdobeAAMDetect: Version: AdobeAAMDetect 1.0.0.0 - SDK 10.6 Support

  FlashPlayer-10.6: Version: 15.0.0.152 - SDK 10.6 Support

  AdobePDFViewerNPAPI: Version: 10.1.10 Support

  DivXBrowserPlugin: Version: 2.2 Support

  Flash Player: Version: 15.0.0.152 - SDK 10.6 Support

  QuickTime Plugin: Version: 7.7.3

  iPhotoPhotocast: Version: 7.0

  SharePointBrowserPlugin: Version: 14.4.1 - SDK 10.6 Support

  AdobePDFViewer: Version: 10.1.10 Support

  Silverlight: Version: 5.1.10411.0 - SDK 10.6 Support

  JavaAppletPlugin: Version: 14.9.0 - SDK 10.7 Check version

Safari Extensions: ?

  DivXHTML5

  Find & Remind

Audio Plug-ins: ?

  BluetoothAudioPlugIn: Version: 1.0 - SDK 10.9

  AirPlay: Version: 2.0 - SDK 10.9

  AppleAVBAudio: Version: 203.2 - SDK 10.9

  iSightAudio: Version: 7.7.3 - SDK 10.9

iTunes Plug-ins: ?

  Quartz Composer Visualizer: Version: 1.4 - SDK 10.9

User Internet Plug-ins ?

  BrowserPlus_2.9.8: Version: 2.9.8 Support

  UploadManager: Version: Unknown

  ContentManager: Version: Unknown

  RocketEngine: Version: Unknown

3rd Party Preference Panes: ?

  Adobe Version Cue CS4  Support

  BrowserPlus  Support

  DivX  Support

  Flash Player  Support

  Flip4Mac WMV  Support

  PenTablet  Support

Time Machine: ?

  Skip System Files: NO

  Auto backup: YES

  Volumes being backed up:

  Macintosh HD: Disk size: 378.40 GB Disk used: 371.64 GB

  Destinations:

  Original Doc Archive [Local] (Last used)

  Total size: 549.96 GB

  Total number of backups: 22

  Oldest backup: 2014-02-16 00:12:34 +0000

  Last backup: 2014-08-04 14:29:16 +0000

  Size of backup disk: Too small

  Backup size 549.96 GB < (Disk used 371.64 GB X 3)

  Time Machine details may not be accurate.

  All volumes being backed up may not be listed.

Top Processes by CPU: ?

      2% WindowServer

      1% Dropbox

      1% fontd

      0% Memory Clean

      0% aosnotifyd

Top Processes by Memory: ?

  262 MB Safari

  115 MB com.apple.IconServicesAgent

  115 MB com.apple.WebKit.WebContent

  78 MB Dock

  74 MB Dropbox

Virtual Memory Information: ?

  1.15 GB Free RAM

  1.75 GB Active RAM

  614 MB Inactive RAM

  501 MB Wired RAM

  372 MB Page-ins

  0 B Page-outs