| Class | Brief description | |
| AccessViolationException | The AccessViolationException class implements an instance of an error occurring during calling an object, which has not been created yet. | |
| ArgumentException | The ArgumentException class implements an instance of an error, occurring when one of the arguments, passed to a property (method), is unavailable. | |
| ArgumentNullException | The ArgumentNullException class implements an instance of an error occurring during an attempt to pass the Null value to a property (method), which does not accept it as an allowed value. | |
| ArgumentOutOfRangeException | The ArgumentOutOfRangeException class implements an instance of an error occurring when the value of one of the arguments passed to a property (method) is out of the boundaries of the allowed range. | |
| ArithmeticException | The ArithmeticException class implements an instance of an error, occurring during performing some arithmetic actions, as well as operations of conversion and transformation. | |
| Array | The Array class implements properties and methods of the Array data type and also variables that have this data type. | |
| BindingManager | The BindingManager class implements the object enabling initialization of value editor settings. | |
| Boolean | The Boolean class represents logical data type. | |
| Broadcast | The Broadcast class implements an object that is used to exchange messages between desktop and web applications. | |
| Char | The Char class represents character data type. | |
| CultureInfo | The CultureInfo class implements an object containing properties and methods for working with regional settings of a specific culture. | |
| Currency | The Currency class represents currency data type. | |
| DateTime | The DateTime class represents date and time. | |
| Debug | The Debug class implements an object that is used to display debugging messages. | |
| Decimal | The Decimal class represents high precision decimal values. | |
| DivideByZeroException | The DivideByZeroException class implements an instance of an error occurring during overflow caused by division by 0. | |
| Double | The Double class represents number with double precision with floating point. | |
| Exception | The Exception class represents a base class for all exceptions, which may be thrown during execution of a custom code. | |
| ExpressionStringHandler | The ExpressionStringHandler class contains methods that are used to implement events that occur on converting expression elements. | |
| Guid | The Guid class implements properties and methods of the Guid data type and also variables that have this data type. | |
| GuidGenerator | The GuidGenerator class implements a generator of global unique identifiers (GUID). | |
| IndexOutOfRangeException | The IndexOutOfRangeException class implements an instance of an error occurring during calling an array element with the index out of array bounds. | |
| Int64 | The Int64 class implements properties and methods of the Int64 data type and also variables that have this data type. | |
| Integer | The Integer class represents integer data type. | |
| JsonArrayBuilder | The JsonArrayBuilder class implements a new JSON array. | |
| JsonDocument | The JsonDocument class implements an object that is used to work with JSON structures. | |
| JsonObjectBuilder | The JsonObjectBuilder class implements a new JSON object. | |
| Matrix | The Matrix class is a basic class used to create dynamic matrices with data. | |
| MatrixFactory | The MatrixFactory class is used to create a matrix structure. | |
| NotFiniteNumberException | The NotFiniteNumberException class implements an instance of an error, occurring, when as a result of some actions, the output value is positive infinity, negative infinity, or is not a number (NaN). | |
| Object | The Object class is basic for all classes and types used in the Fore language. | |
| OleException | The OleException class implements an instance of an error occurring during working with OLE objects. | |
| OverflowException | The OverflowException class implements an instance of the error occurring when the internal buffer is overflowed. | |
| Regex | The Regex class allows for working with text information using regular expressions. | |
| RuntimeInterop | Static properties of the RuntimeInterop class are used to get information on the last error occurred within the current application stream. | |
| StackOverflowException | The StackOverflowException class implements an instance of an error occurring during stack overflow. | |
| String | The String class represents string data type. | |
| SysEventLog | The SysEventLog class is used to create records in Windows event log. | |
| SysSettings | The SysSettings class implements an object used to work with BI server settings file settings.xml. | |
| TextConverter | The TextConverter class implements a converter used to convert text to various formats. | |
| TimeSpan | The TimeSpan class represents time interval. | |
| Variant | The Variant class implements properties and methods of the Variant data type and also variables that have this data type. | |
| Win32Exception | The Win32Exception class implements an instance of an error, occurring during the work of Windows API functions. |
See also: