LemonPOS: Linux Point of Sale

Jack Wallen
Jan 3, 2010
Updated • Jan 19, 2013

I work with Quickbooks Point of Sale which is considered, by most, to be the de facto standard of Point of Sale systems. The clients that use Quickbooks POS are medium to large businesses that can actually afford both the software and the support necessary to ensure the system is up and running 24/7. But for those clients that don't have the budget to afford such a system, I have to turn to other choices. For the longest time I had adopted NolaPro - which wasn't open source and difficult to teach. That isn't to say it's a bad choice, it's not. In fact NolaPro is an outstanding system that has a TON of features (including a full accounting, ecommerce, and inventory system). But for those who need a simpler inventory/POS system, and want this system to run on the Linux operating system, what is the best option? One choice is LemonPOS.

When I first ran into LemonPOS it had serious installation issues. That has since gone away. Now, getting an instance of Lemon POS is not nearly as difficult as you would expect. In this tutorial I am going to show you how to get LemonPOS up and running and then show you around the tool a bit. NOTE: You will need MySQL up and running in order for LemonPOS to work.

Getting and installing

There are two ways to install this tool: Using Synaptic (or yum, or apt-get, or the Ubuntu Software Center) or installing from source. Although installing with a package manager is the easiest method, you will still need to download the source in order to get the database installed. So, let's do this in two phase: Package manager and source.

Open up your favorite package manager and do a search for lemonpos. You might notice that two packages come up: LemonPOS and Squeeze. Both of these need to be installed. Squeeze is the LemonPOS manager. Without Squeeze you will not be able to add items to the inventory to be sold. So mark both for installation and apply the changes.

After these packages are installed you will need to download the source. This file will be a bz2 file which you will have to first decompress. Save this file in your ~/Downloads directory. Open up a terminal and follow these steps:

  1. Change to the ~/Downloads directory with the command cd ~/Downloads
  2. Decompress the file with the command bunzip2 lemonpos-persa-XXX.tar.bz2 Where XXX is the release number.
  3. Unpack the file with the command tar xfv lemonpos-persa-XXX.tar Where XXX is the release number.
  4. Change into the database_resources subdirectory of the newly created directory with the command cd persa/database_resources
  5. Install the databases with the command cat lemon_mysql.sql | mysql -u root -p
  6. When prompted, enter the MySQL administrator password and hit the Enter key

Now you are ready to start up the LemonPOS or Squeeze.


Figure 1

You will find Squeeze (and LemonPOS) located in the Office sub-menu of the Applications menu. When you start up Squeeze you will not be asked for a password (that has already been taken care of during the database installation).

In this tool (see Figure 1) you can take care of all administration tasks for LemonPOS. In fact, you will need to take care of these tasks before LemonPOS is of any use to you.

The first things you will want to do is to create Categories, Vendors, Clients, and Products to be worked with and sold. As you create these they will be populated into LemonPOS. Of course you can not really use LemonPOS until you have your items created. Naturally the type of items you create will depend upon the business you run.

Figure 2

It should be noted, however, that when you are creating a Product in the Product Editor (see Figure 2) you have to fill out all of the data. Until you have all necessary data filled out, the OK button will be grayed out. Initially I had trouble setting up products that had no cost to the business (such as services) but had a cost to the customer. To get around this fill everything out, create a Profit, click the $ button to calculate Public price (based on Profit %), and then go back to the Public price and change the figure.

Once you have all of your clients, vendors, categories, and products added you are ready to open up LemonPOS. NOTE: You can start LemonPOS at any time. You can do a partial set up of your inventory and then go back and add to it. You will also re-visit Squeeze when you need to check in products.


Figure 3

The LemonPOS can be started by going to the same sub-directory you started Squeeze from. When you start LemonPOS you should instantly see that the software is fairly user-friendly (see Figure 3).

In Figure 3 I have created an item for the Ubuntu Desktop Software. I did this just for an example. To sell this item you would find the item (filtering with various tools) and then click the item. To sell multiple copies of the item you can keep clicking the item until you have the amount of items listed you want to sell. When you have all the items listed to be sold either enter the amount of cash taken and hit the Enter key or click Card and enter the card number and the Authorization number (to be taken from a credit card terminal - LemonPOS does not yet have any means of directly transacting with credit cards).

From this same window you can (and should) set up your printer. If you do not configure the printer there will be no customer receipt. To configure your printer (and other options) click the Configure Lemon link in the left navigation.

Final thoughts

Although not on the level as Quickbooks POS, LemonPOS does have a lot to offer small businesses (or even single consultant businesses that need to keep track of work, inventory, and sales). If you're looking for a free, open source POS that has a lot of potential, give LemonPOS a try.


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  1. William said on November 11, 2011 at 12:07 pm

    How does it work with barcodes? Is it stand alone accounting or does in integrate with GnuCash?

    1. Tyler said on July 13, 2015 at 12:36 pm

      I haven’t read anything about barcodes, but I do know POSper supports both those and card readers.

  2. Jao Madn said on February 2, 2011 at 6:41 pm

    Some Additional info dont install lemonpos througth ubuntu repo. the squeeze has some problem functioning when accesing database try add users and u will know..when i try i will hang up..ill try it in ubuntu 10.04 and.10.10 kubuntu since it depencies best on kubuntu..

    My solution is i used the source code and compile and install.. at it works.

  3. Zack said on January 6, 2011 at 7:05 pm

    We went with Volante Systems POS on Linux and it works very well:

  4. 507 Media Studios said on October 23, 2010 at 9:38 pm

    Hi Jack,

    Nice guide, thanks for helping out. One thing you forgot to mention was the default username and password to login into squeeze, which actually are Username: admin and Password: linux

  5. Anonymous said on May 11, 2010 at 12:33 am

    Looks like Open Bravo POS!

  6. bbto said on May 6, 2010 at 5:29 pm

    Hi, there is an error installing lemonpos on Ubuntu 10.04 any help?

  7. Gary said on January 5, 2010 at 6:04 pm

    People looking for POS software may wish to checkout (no pun intended) Quasar. Nice system, and while not free is much much less than QB POS. I am not in any way affiliated with Linux Canada.


  8. A. Lurker said on January 5, 2010 at 7:44 am

    Why should I invest in a POS system that relies on MySQL? Wouldn’t it be wise to wait until the current MySQL/SUN/Oracle mess is resolved?

    1. the Goat said on January 5, 2010 at 6:34 pm

      Because LemonPOS is open source and therefore NOT limited to using only mysql.

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