ChannelScript (abbreviated as CHANS) is the system used by the Wii's system menu to display "dynamic" banners. It seems to be some form of interpreted bytecode, which resembles JavaScript in many ways. The same bytecode can also apparently be interpreted on the Starlet while the Wii is off; this is performed by the /dev/kd module and forms the basis of WiiConnect24.

This page shall describe said bytecode and the header for CHANS files. You may find a CHANS file in the News Channel as content index 5.

Here is what is known of the structure for the header:

This data is in no way 100% complete, or even 100% proven.

typedef struct {
        //START: Main Header
        u32     head; // 0x00000000
        u32     version; // 0x00000004
        u32     file_size; // 0x00000008
        u8      unk[0x14]; // 0x0000000C
        //END: Main Header

        // All offsets are from 0x20
        u32     unk10; // 0x00000020
        u32     unk20; // 0x00000024
        u32     unk30; // 0x00000028

        // First data section (this is the bytecode)
        u32     fds_size;  // 0x0000002C
        u32     fds_offset; // 0x00000030

        u32     table4_count; // 0x00000034

        u32     unk5; // 0x00000038
        u32     unk6; // 0x0000003C

        // Table 1 is made up of 8 byte chunks
        u32     table1_count; // 0x00000040
        u32     table1_offset; // 0x00000044

        // Table 2 is the method name list
        u32     table2_count; // 0x00000048
        u32     table2_offset; // 0x0000004C

        // Table 3 is a string literal table.
        // Each string is in utf-16, preceded by a u16 which specifies BYTE length of utf-18 string
        u32     table3_count; // 0x00000050
        u32     table3_offset; // 0x00000054

        // Possibly unused table
        u32     unk7; // 0x00000058
        u32     unk8; // 0x0000005C
        u32     table4_offset; // 0x00000060

        u32     unk9_offset; // 0x00000064
        u32 unk11; // 0x00000068
        u32 unk12;  // 0x0000006C
        u8 unk13[0x10]; // 0x00000070

} chans_header;

typedef struct {
        u8      length;
        u8      padding;
        u16     offset;
} table2_entry;

Here's a list of method names extracted from the IOS "KD" module:

length, join, new2d, pop, push, shift, slice, unshift

getDate, getDay, getFullYear, getHours, getMilliseconds, getMinutes, getMonth, getSeconds, getTime, getRTC

charAt, *fromCharCode, indexOf, lastIndexOf, replace, search, slice, split, toLowerCase, toUpperCase

*create, seek, skip, isEqual, getLength, setLength, fill, getU8, getU16, getU32, getS8, getS16, getS32, getS64, setU8,
setU16, setU32, setS8, setS16, setS32, setS64, getString, getWString, setString, setWString, getBlob, setBlob, getHexString,
copyRangeFrom, calcSHA1Digest, calcMD5Digest, calcCRC16, calcCRC32, calcHMAC, calcRangeSHA1Digest,
calcRangeMD5Digest, calcRangeCRC16, calcRangeCRC32, calcRangeHMAC, pack, unpack

verbose, logLevel, stat_result, stat_permission, stat_lastCriticalError, stat_newMsgFlag, stat_taskStage, stat_numErrors,
stat_numMsgSent, stat_numMsgReceived, stat_numMsgSaved, stat_numMsgRejected, stat_numMsgFiltered, stat_countMailChk,
stat_countMailRcv, stat_countMailSav, stat_countMailSnd, stat_countDL, stat_countEstablished, stat_mailTaskTrace,
stat_dlTaskTrace, stat_countMailPrc, stat_countForceRecv, stat_countMailIdle, stat_countScriptExec, stat_errorLog

getMyUserId, getReceivedMsg, getReplyMsg, getStorage, getRandom, isStandbyMode, launchApplication, getHomeDir,
isSucceed, isFailed

getId getType getAppId readToId readToAddr readFromAddr getFromId readFromId readSubject readAltName readText
getCommand getScriptParameter getScriptTtl getTag getSequenceNumber getDate hasMii readField readAttached
getNumAttached getAttachedSize getAttachedType

setToId setToAddr setSubject setAltName setMBNoReply setMBRegDate setMBDelay setText setLedPattern setIconNewSign
setIconNewSignEx setDesignatedTime setExecScript setTag setSequenceNumber copyMiiFrom copyFromFrom setAttached
commit _commitNow

status name fdId wiiId mailAddr

check isEstablished isWiiFriend

read _write _update _delete isExist searchBy Id searchByAddr getNum getNumReg getNumRegisterd getNumEst getNumEstablished

TODO: A lot! Keep adding data, people!