PROTEUS License Manager
Delphi VCL

screen code free pexels CC 


Proteus library is a licensing system for Delphi. It helps you sell your program to your customers.
With Proteus library you can create demo/trial versions of your application that are time-limited or feature-limited.




  • Create trials, rentals, and pay-per-use applications.
  • Immediate software activation via phone, email, or Internet.
  • Allows user to extend a trial, rental or lease license for an additional period of time.
  • Allows user to upgrade from rental/lease to a full license at any time.
  • Allows user full or partial access to your program's features/modules. The customer can activate/purchase additional features/module later.
  • Prevent fraudulent purchases. Disable "stolen keys".

    Typical example:

    Protect your application with Protes and deliver it to your customers where it will work as Trail. After 14 days it will switch to Demo mode where program's functionality is severely crippled ("Save project" function does not work), and a "nag" screen is shown.

    Upon payment the customer can receive the Unlock Key. The customer enters the key into the program and the program switches from Demo to Registered mode (fully functional).

    The key is a string (example: *P083BkdMTU1NfE5MTU1NTU1Nbn90dH94eX97fHw=*) so it can be easily transmited via email.

    Delphi trial protection and licensing system Pascal library

    Delphi licensing system for trial and protection

    Additional capabilities/examples

    Temporary vs permanent license:

    The customer can :

    Limited access to your software modules:

    Based on which license the customer purchased, he can receive an unlock key that unlocks:


    One line to rule them all

    Proteus is really easy to use: you only have to write a single one line of code in order to integrate Proteus in your application:

    procedure TMyForm.FormCreate(Sender: TObject);

    To generate keys for your customers, all you have to do is to call Certificate.GeenerateKey;


    Infinite flexibility

    Proteus understands "certificates". A certificate is a record that tells the program the current status of the license (license state: trial/demo/full, license expiration date, modules purchased/unlocked, customer name, etc).

    The license key string that you send to the customer is nothing else than this record (certificate) converted from binary to string.

    Usually you will setup a "global" certificate and use it to generate keys for all your customers.
    OR you can generate new certificates for "special" customers. For example, you want to keep the licensing model simple and you have just one license type: monthly subscriptions for $199. But one customer wants to purchase a permanent license. With just few clicks in your key generator tool, you can create a custom certificate for this customer and sent it via email in no time.

    license key trial protection generator source code 
    (Example of possible application for generating license)


    If the keys are leaked by your customers on serial/cracking web sites you can immediately take measure by invalidating the leaked keys. Also, Proteus has measures put in place to make sure the customer does not try to temper with the Trial period or with the license key he has received. The actual key data is encrypted (you can use your own ecryption methods) and check sums are calculated.



    Download the source code of the demo application (compiled EXE also available). The download also contains the headers of the Proteus Delphi library.



    The Delphi source code is available for $99. It includes the library itself and a simple license/key generator. 
    We only accept orders from corporate customers (companies with established website). We don't accept orders from anonymous emails (such as Gmail, Yahoo, MSN). We might request some identity proof (like ID/passport) if your business identity is not clear.

    Delphi compatibility

    How to use Proteus License Manager?



    Q: Is it possible to tie a license to a certain Product version. For example, if we release a major version, the user needs to pay for a new license.
    A: Yes. You can also allow the key for v4.0 to be used with an older version (v3, v2, etc). For this set Certificate.UnlockDown := true;

    Q: Is it possible to have different types of licenses - trial, pro, enterprise, and corporate with different features on each?
    A: Yes.

    Q: Can the key generation process be completely automated and integrated with a web site/server? The user pays and the site generates a license so they can start using the software straight away?
    A: Yes. We built Proteus with this feature in mind.
         Just run the key generator on your server (the key generator could be a small app that you build that calls Certificate.GenerateKey). When you have a sale, just make your webpage send the customer name to your key generator. The generated key could be shown in the web browser or sent via email.