From Mantis Bug Tracker :

ZEOS - 6.6.2 RC
===============
- 0000022: [general] Split ZPlainMysql.inc
- 0000023: [component] Problem using WideStrings and ADO protocol when chaging any WideString Field Data, same nature as Issue 0010 (fduenas)
- 0000016: [core] Integer field treated as Largeint
- 0000005: [postgresql] [memory] Memory grow when connection failed

- 0000013: [interbase/firebird] can not use a string as parameter value for integer/long parameters
- 0000019: [interbase/firebird] string parameters don't work for blob fields
- 0000033: [interbase/firebird] Fixes a bug in UpdateString procedure for ZDbcInterbase6Utils
- 0000034: [interbase/firebird] Lookup field make other field in TZQuery lost the value (disappear from display but still exists in database)
- 0000020: [interbase/firebird] second call to stored proc fail with a parameter mismatch error (cipto_kh)
- 0000040: [component] Error in conversion int64 to variant in InternalPost on Delphi/C++Builder 5 (ZAbstractDataset.pas)
- 0000042: [general] Using the same component (TZStoredProcedure) after ExecProc then using Open it will crash (cipto_kh)
- 0000037: [component] ZEOS AND LAZARUS 0.9.23 and FPC 2.1.3 WIN32 ERROR
- 0000038: [component] Can't open sqlite databases with Umlauts like äöü in path (fixed)
- 0000046: [component] fpc 2.1.4 cannot compile ZAbstractRODataset.pas
- 0000028: [interbase/firebird] TZInterbase6DatabaseMetadata.HasNoWildcards - wrong result (cipto_kh)
- 0000055: [component] Wrong index variable used when doing "refresh" in ZUpdateSQL component , patch included
- 0000050: [postgresql] 'Access Violation' error on ZQuery.Open on table that has columns with non-standard type
- 0000041: [postgresql] TZPostgreSQLDatabaseMetadata.GetSequences return not schema-qualified sequence list (ZDbcPostgreSqlMetadata.pas)
- 0000049: [core] Lookup fields with int64 data type not work in Delphi/C++Builder 5
- 0000007: [interbase/firebird] TZSequence error, value from prior database (cipto_kh)
- 0000048: [general] TZSQLProcessor does not react when Script text is not properly delimited
- 0000056: [component] Protection fault when doing an EAbort exception in BeforeConnect of TZConnection (patch incl.)
- 0000064: [parsesql] Mysql /*! ...*/ special comments shouldn't be considered as real comments
- 0000063: [component] TZSQLProcessor and comments handling
- 0000061: [component] Wrong data returning in select
- 0000065: [general] FPC 2.2 doesn't compile
- 0000068: [postgresql] Wrong datatype declared
- 0000043: [component] ReadOnlyQuery + TDataSetProvider = Blank fields on details
- 0000059: [component] ZQuery-DSP-CDS empty field data fetched while using incremental fetching (PacketRecords>0)
- 0000027: [interbase/firebird] problem handling DEFAULT NULL in domain *AND* in table
- 0000069: [general] Compiler Warnings in Delphi 2006
- 0000071: [interbase/firebird] Floating point not display correctly (cipto_kh)
- 0000076: [mysql] SSL Connection Error
- 0000075: [sqlite] Memory Error Detected
- 0000070: [general] Missing license files
- 0000079: [dbc] Typo in SQl statement in TZInterbase6Connection.Open;
- 0000017: [mysql] LargeInt fields treated as Variant
- 0000060: [sqlite] Memory leaks in sqlite-3 driver

Not in Mantis Bug Tracker :

Bugs

- Metadata (mdTables) was missing remarks data (http://zeos.firmos.at/viewtopic.php?t=1567)

- Memory leaks (http://zeos.firmos.at/viewtopic.php?t=1408)

- Correction of child dataset refresh (http://zeos.firmos.at/viewtopic.php?t=1381)

- Set autocommit issue when transaction isolation=tiNone (http://zeos.firmos.at/viewtopic.php?t=1251)

- TZAdoDatabaseMetadata.GetColumns doesn't fetch database and schema names. (http://zeos.firmos.at/viewtopic.php?t=1252)

- TZRowAccessor.CompareBuffers didn't work for stUnicodeStreams (http://zeos.firmos.at/viewtopic.php?t=1254)

- TZSQLStrings.StatementCount = 1 when the statement is empty (http://zeos.firmos.at/viewtopic.php?t=1228)
- Error handling empty string values (makes them NULLS) (http://zeos.firmos.at/viewtopic.php?t=1255)

- Read blob truncates last byte for ADO (http://zeos.firmos.at/viewtopic.php?t=1250)

- Close/Open sequence replaced by refresh in TZAbstractRODataset.RefreshParams (http://zeos.firmos.at/viewtopic.php?t=1093)

- Wrong mysql version reference in GetMoreResults function

- Required should be false if a field is not writable (http://zeos.firmos.at/viewtopic.php?t=767)

- Avoid open/close of detail dataset on edit of master dataset (http://zeos.firmos.at/viewtopic.php?t=1093)

- FreeAndNil fix in ZSequence - (http://zeos.firmos.at/viewtopic.php?t=1108)

- Mysql fixes by HeidiSQL Team (Repository viewer at http://fisheye3.cenqua.com/changelog/heidisql)

* Avoid an access violation within a for loop which got run once even when there were 0 columns in a result. (HeidiSql rev. 993)

* Fix bug "SHOW FULL PROCESSLIST on mysql v4 server messes Zeos up". (HeidiSql rev. 775 and 900)

* Fix handling default values. (HeidiSql rev. 505)

* Zeos did not recognize UNSIGNED ZEROFILL columns as being UNSIGNED. (HeidiSql rev. 521)

New Features

- All mysql_options() and connection clientflag settings can now be set using TZConnection.Properties (http://zeos.firmos.at/viewtopic.php?t=1528)

- Updated indonesian translations

- Added Russian translation
- Use Mysql_real_escape_string instead of mysql_escape_string when executing mysql emulated prepared statements

- Added IZConnection.EscapeString function. This funtion returns a string that can be used in SQL statements. Uses Mysql_real_escape_string or Mysql_escape_string functions for mysql databases and EncodeCString function for other databases

- FPC changes -> now zeoslib also works with MSEIDE - By MSEIDE team (http://www.homepage.bluewin.ch/msegui)

- Added all reserved words, functions from mysql 5.1 documentation to metadata GetXXX functions (http://zeos.firmos.at/viewtopic.php?t=1213)
- Replaced 'Select' in Getversion to Native library call.

- Added support for Mysql SSL connections

- Added TZConnection.GetColumnNames function (http://zeos.firmos.at/viewtopic.php?t=1127)

- Added Delphi2007 package files (http://zeos.firmos.at/viewtopic.php?t=1173)

- Changed PingServer behaviour : Only return false when ping fails. No exception. This function is a check, so it should be allowed to return false. On demand of HeidiSql team.

- Modified Readme text for mysql embedded server example
- Added Multiple resultset support on Dbc level (http://zeos.firmos.at/viewtopic.php?t=459 and http://zeos.firmos.at/viewtopic.php?t=912)

- ZDataset Events in Lazarus (http://zeos.firmos.at/viewtopic.php?t=1130)

- New Features by HeidiSQL Team (Repository viewer at http://fisheye3.cenqua.com/changelog/heidisql)

* Added unknown data types from mysql_com.h. (HeidiSQL rev. 835)

* Make ConvertMySQLHandleToSQLType() more readable (HeidiSql rev. 676)

* Ignore columns that do not originate from the table when resolving updates (HeidiSql rev. 555)

* Added function TZAbstractResultSetMetadata.HasDefaultValue (HeidiSql rev. 504)

* TZConnection.Reconnect added (HeidiSql rev. 53)

Internal changes

- Release build script has been rewritten

- Added SVN ant utilities to repository so build scripts should run on a standard Ant installation
- Fixed the automatic build system and test suite. Works now certainly for D5, D7, D2006, D2007

- Added Lazarus/Fpc to the automatic build system. Test suite is not available, however. Package *.pas files are necessary for automated build system.

- Removed some compiler warnings and unused units.

- Start of the zeoslib documentation project using doxygen.