See also: Why use uCalc FMP instead of another parser? uCalc Fast Math Parser product page 1) uCalc allows runtime math, which I've found invaluable for many of my applications. This ability provides me a method of meeting my customer needs by having a level of programmability that is impossible otherwise. I get curve-balls thrown at me all the time. With uCalc I can usually hit the ball without having to change my application - a very expensive process in the Aerospace world. 2) The language building feature is not useful to me, at least not yet.  The new ability to change syntax is useful. 3) Multithreading is very useful. 4) One big difference between uCalc and other math parsers I've examined is the ability to handle strings - I don't think any of them do it. This feature is critical to me. As an aside, I've had really good luck with uCalc after we figured out how to use it in LabVIEW ... It has proved very stable and capable. Derek Kelm Ball Aerospace & Technologies Corp. In my opinion, these are the main features/advantages of the uCalc FMP: (1) Ease of use: It is very attractive to find a tool that you can start using quickly. Even though uCalc FMP is very powerful and as such it takes some time to learn to take advantage of all its power, it just takes a few minutes to start being productive with it. (2) Flexibility: uCalc FMP allows me to implement the algorithms I need in the way that is most efficient for my application. I can use the built-in functions, expand that built-in functions list, pre-define my own functions, or define expressions at run-time. (3) Support: Regardless of the documentation (which is excellent), nothing helps more than getting the answer to your question straight from an expert.  It not only gives more meaning to the documented behavior, but gives you practical insights that are invaluable. Furthermore, being able to make suggestions about the future development of the tool and seeing that feedback being acted upon reinforces the sense that you made the right decision when selecting uCalc FMP. (4) Value: The main reasons for buying a math parser instead of trying to build one myself are the breadth of features, its stability and the speed of its execution. Math parsers are very complex libraries. Complexity usually makes it hard (and/or expensive) to attain fast execution. uCalc FMP is the complete package at an attractive price. That's value. J.O. Sandia National Laboratories Easy to use and well-documented, even for non-programmers. Wolfgang Schett uCalc is an excellent solution to the problem of runtime definition of equations. We looked through many different potential solutions for a math parser and chose uCalc several years ago due to several key factors. Primarly, uCalc is extremely fast and provides timely support (which other vendors and free solutions lacked). uCalc also supports the definition of custom functions which dramatically increases its usefulness. We have been using uCalc 2.0 for over 5 years and have over 10,000+ installs on customer's machines, with no problems. The simplicity of the install is critical in ensuring a smooth installation on the customer's machines. We just upgraded to uCalc 2.95 and it is even better. Excellent job! Philip Mayfield www.sigmazone.com uCalc has two features that are very important to us: 1. It is fast. I have developed a specialized database server that is used to store billions of records, and I use uCalc to allow users to operate on fields and rows with mathematical expressions; 2. It is very easy to integrate with other programs. Francisco Rodrigues Stone Age Tech Below are the features that I found particularly attractive. It has been awhile since I googled math parsers and selected FMP, but as I remember, there were few or no other choices that had the features I wanted. 1. It parses and evaluates fairly general mathematical expressions. 2. It allows users to define their own functions, which can be called by the parser. 3. Fast. Part of being fast for my application is that it parses and evaluates in two separate steps. This is because I use it to parse multiple expressions, which are then each evaluated many times. 4. It is a DLL callable from either Visual Basic or C++. 5. It is fairly inexpensive and licensed so only the developer needs to pay the licensing fee; there is not an extra fee for letting others use an application developed with it. 6. It allows user defined variables in the expressions. Tom H. For our business software, uCalc FMP allowed us to implement a flexible calculation schema instead of static data fields. We hat superior user acceptance, because the calculation sheet now has real Spreadsheet Look-And-Feel, a great advantage ahead of our competition. Gerhard Achrainer I am using uCalc just for hobby, but basically I like following features: - Easy to implement, I am using C++ Builder ver 6 - Easy to generate own functions and variables - Catches pretty well exceptions and does not seem to have too many bugs, and it is also rather reliable. I have not been able to make it crash. Jarkko Halme We use the UCALC Fast Math Parser in a Visual C++ application for 'realtime' lighting control where it must do a few thousand expression evaluations (and as many variable updates) per second. We've been very impressed with the performance of the library and the ability to easily extend it with user-defined functions. Jeff Burke, HyperMedia Studio University of California, Los Angeles Ok, to me, in order of importance: 1- SPEED! Nothing can compare with uCalc 2- C++Builder support 3- User-defined variables (that gives total freedom to end users) 4- Also incredibly important in my domain (volcano monitoring) is that since I have integrated uCalc, now every user can modify the rules to process the incoming data. Before uCalc, well, I had to modify the source code, recompile the application, and redistribute it. Now they're free to act independently on the core of the application (formulas) without depending on me. This is the most valuable feature of all. ... Anyway, I can't imagine myself someday switch to anything else. Steve Jordi Very useful and easy to use. Anita R. It saved me a great deal of time and effort, and considerable stress as I was not looking forward to the prospect of programming the arithmetic parsing in VC++ myself. Dr. K. Brazier University of Liverpool We use UCALC in a Delphi flight data system which proactively detects engine problems before they happen and monitors the way in which aircraft are flown. Typically, this can mean 5 million calculations per aircraft, with UCALC, this takes just a few minutes. Most impressive. Paul Harrison British Airways