对于我们这些刚接触Symbian的人来说，其中一个比较讨厌的问题也就是什么什么kon了。简单的说，不同的kon代表不同的接口类型。例如：

EIKON: original EPOC32 UI (User Interface)
UIKON: "generic" Symbian OS UI
AIKON: S80 1.0 (Nokia 9210) UI
AVKON: S60 UI
CKON: S80 2.0 (9300/9500) & 7710 UI

Qikon UIQ UI。

关于它们的详细介绍，请参看下面的文章，懒得翻译了，直接贴出来了。

The Common Framework

Qikon and Avkon are the names of the UI-specific application framework
layers implemented on top of the common Symbian OS UI framework,
which is called Uikon. Qikon and Avkon implement framework classes
defined in Uikon which must be overridden further by application writers.
They also define many UI-specific controls, like dialogs, list boxes and
editors that can be reused in applications.
Uikon provides the base classes for the three fundamental UI classes:
the application (CEikApplication), the document (CEikDocument)
and the application UI (CEikAppUi). All Series 60 and UIQ applications
minimally need to define their own classes that derive from these.
However, they must not derive directly from the Uikon base classes, but
from the UI-specific implementations of them.
These implementations have the same name as the Uikon classes, but
in UIQ the CEik prefix is replaced with CQik, and Series 60 uses CAkn:

                                          Application                         Document                            App UI
Symbian OS (Uikon)    CEikApplication               CEikDocument                    CEikAppUi
Series 60 (Avkon)         CAknApplication              CAknDocument                   CAknAppUi/CAknViewAppUi
UIQ (Qikon)                    CQikApplication               CQikDocument                   CQikAppUi

The convention of using a Qik or Akn prefix is used throughout UIQ
and Series 60 to identify UI-specific classes, headers and libraries. In
general, a type, header or library without such a prefix is part of Symbian
OS, and is present in both UIs. There are some exceptions to this, notably
avkon, which appears in a few filenames like avkon.lib which is the
main Series 60 UI library, and avkon.hrh which holds the Series 60
resource constants.With the exception of the app UI, there are very few differences
between the Uikon, Qikon and Avkon implementations of these three
classes.