Free memory usage software for mac

iStat Menus 1.3 is a powerful and popular utility which monitors your entire system right from your menubar, with 8 separate and highly configurable menu extras. You'll always know exactly what's going on inside your Mac!

You'll be able to view your CPU usage, memory usage, disk usage and activity, network monitors, the internal temperature of your Mac, fan speeds, bluetooth status, and more. All from the Apple Menubar!

System Manager came into being from a desire to roll the functionality of several of my favourite apps into one app, increase the functionality of a few of them, and free up some Dock space. Other functions were, and will be, added to increase its overall usefullness such as system log monitoring, file/folder permissions control, trash management, and possible improvements to Process Monitoring to name a few.
System Manager combines some of the best features from a variety of other monitoring apps all rolled into one application.
Main features:
- CPU Usage (Dual)
- System Load levels
- Memory Usage
- Network Activity
- Process listing with kill and renice a process
- System Preference Pane launching
- Uptime display
- IP Number display
- Classic status display in MenuBar, Dock, or any graph
- Launch and Shutdown Classic
Enhancements:
- you can disable CPU Monitor temp checking to improve performance
- you can show the CPU Monitor temperature in Celsius or Fahrenheit
- fixed a CPU Monitor ghosting remnant when drawing with Transparancy
- added pref to show/hide large CPU percentage readout seperately
- added pref to use non-transparent CPU border alarms
- dded transparent background option to the Load Monitor
- etwork monitor is now switchable amongst installed interfaces
- added Dock icon menuitem to select monitored network interface
- network data in and out values/plots/scale now reflect per sec values
- network refresh rate is adjustable instead of hard wired 2 seconds
- fixed a memory leak in the network monitor
- uptime monitor now remembers, displays and saves longest running uptime
- user definable large display font on the General preference tab
- moved the "Dock Icon Shows" radio buttons to the General pref tab
- fixed display of Classic status indicator when using graph transparency
- other minor performance improvements

MenuMeters 1.4b3 is known as a set of useful tools for monitoring CPU, memory, disk, and network in MacOS X. Although there are numerous other programs which do the same thing, none had quite the feature set I was looking for. Most were windows that sat in a corner or on the desktop, which are inevitably obscured by document windows on a PowerBook's small screen. Those monitors which used the menubar mostly used the NSStatusItem API, which has the annoying tendency to totally reorder my menubar on every login.

The MenuMeters monitors are true SystemUIServer plugins (also known as Menu Extras). This means they can be reordered using command-drag and remember their positions in the menubar across logins and restarts. MenuMeters is open source freeware released under the GNU General Public License (GPL).

Major Features:

1. The CPU Meter can display system load both as a total percentage, or broken out as user and system time. It can also graph user and system load and display the load as a "thermometer". The menu for the CPU Meter contains several pieces of information I like to have a single click away (uptime, load average, open Activity Monitor.app, open Console.app).
2. The Disk Activity Meter displays disk activity to local disks on the system (anything that is a IOKit BlockStorage driver). It is hotplug aware, and will show activity on FireWire and USB disks as they are mounted. The Disk Meter menu shows volume space details for local drives (it does not display mounted network volumes for speed reasons).
3. The Memory Meter can display current memory usage as either a pie chart, thermometer, history graph, or as used/free totals. The Memory Meter menu shows a breakdown of current memory usage and VM statistics. The Memory Meter can optionally display a paging indicator light.
4. The Net Meter can display network throughput as arrows, bytes per second, and/or as a graph. Both the arrows and the graph are scaled using a user-selected scaling factor and calculation. Scaling can be done on the basis of actual link speed reported by the network interface or peak traffic and can use one of several scaling calculations. The Net Meter menu shows current interfaces and their status. Interface information is gathered from the SystemConfiguraton framework and thus is Mac OS X network location aware

Send SMS (Short Message System) text messages from your Mac to mobile phones, without needing to connect or sync your own phone to your Mac. Messages that you send with smsZap are passed over the Internet to our SMS service centre.
Enjoy the upgrade of going from your cramped mobile keypad to the full keyboard of your Mac, or avoid touching the keyboard altogether and simply copy and paste your message to an SMS (e.g. fire off a news headline from a web page to a friend, or copy an address from an email to your own phone).
smsZap is FREEWARE but does require credits in order to send out messages (these can be bought from smszap.com).
Main features:
- Low cost mobile messaging. Save money on international text messages (you may also make considerable savings on local / national text messaging too) and send messages whilst you are travelling without paying any roaming charges.
- Send messages quickly from your computer without having to awkwardly type them on a mobile phone keypad.
- Integrates with the Apple Address Book. Access all your contacts from within smsZap: click their name and the number you want to send the text message, type your message and hit send!
- Track the progress of your messages in real-time as they are sent and get delivery confirmation when the message arrives.
- Use SMS even in areas where you cant even get a mobile signal.
- Send official SMS messages that need to be stamped with your company name as the sender.
- Copy and paste information from Safari, Mail (or any other application) to your own phone or a friends.
- Keep messages off your phones memory for security or privacy reasons.
- Very resource efficient: only a 276 KB download that uses minimal hard disk space, and will go unnoticed from a CPU / memory usage point of view.
Enhancements:
- Fixed some networking issues that affected a few users whilst creating an account in the Setup Assistant.
- Some minor enhancements to prevent smsZap from freezing when launched (a problem found to affect a minority of users).

Memory Smiley is a free Yahoo widget thatfeatures a smiley changing its mood as your memory usage changes.

System requirements:
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Enhancements
- Freeware.

iStat memory is a simple widget to monitor memory usage with a striking design and two different views.
Switching between the simple and advanced views is merely a matter of clicking on the dials centre. Available for both PC and Mac Yahoo! Widget Engine users.
Note: The interface design is different for each platform.
System requirements:
- Yahoo! Widget Engine

A small, yet powerful widget that keeps track of your memory usage. qMEM is resizable and can be configured to fit just your needs.
You can use qMEM as a short memory history or simply as a quick way of estimating your current memory usage.
Enhancements:
- Fixed bug that would make the widget not work on computers with more then 1G of memory (Thanks to Tom McIntosh and Ian Hopkins for helping debug this issue).
- Fixed the color of the text below the memory bar.
- Replaced total memory with inactive memory in the textual memory representation.
- Added possibility to show inactive memory as part of the graph.
- Fixed issue that would make the widget show wrong memory numbers when near 100% of the memory was in use.

X Res