Comment 11 for bug 93603

This is quite easy to do; here are the results.

1)On Gutsy (latest update), the list of extensions that can be installed separately may be obtained by doing:
   apt-get install php5-[TAB]

php5-imagick php5-librdf php5-memcache php5-odbc php5-snmp
php5-sybase php5-xcache php5-auth-pam php5-curl php5-imap
php5-mapscript php5-mhash php5-pgsql php5-sqlite php5-syck
php5-xmlrpc php5-dev php5-interbase php5-maxdb php5-ming
php5-ps php5-sqlite3 php5-tidy php5-xsl php5-clamavlib
php5-gd php5-json php5-mcal php5-mysql php5-pspell
php5-sqlrelay php5-uuid php5-idn php5-ldap php5-mcrypt
php5-mysqli php5-recode php5-suhosin php5-xapian

(I've removed php5-cli and other things which aren't "extensions" from the above).

2)The list of modules built in the main package + installed modules can be obtained by doing "php -m"

Thus, I see the following modules which are part of the main package (I've removed the dups which are installed manually).

bcmath bz2 calendar ctype date dba dom exif
filter ftp gettext hash iconv json libxml mbstring
mime_magic mysqli ncurses openssl pcntl pcre PDO pdo_mysql
pdo_pgsql posix Reflection session shmop SimpleXML soap sockets
SPL standard sysvmsg sysvsem sysvshm tokenizer wddx xml
xmlreader xmlwriter zip zlib

3)The list of available extensions is here: http://www.php.net/manual/en/extensions.php
I've trimmed it down to the following (by removing the windows-specific ones, and the ones already listed above, and anything that is PECL)

bcompiler
SessionPgSQL

dbx SDO-DAS-Relational dBase DB++ FrontBase filePro ibm_db2 Informix Ingres II mSQL
OCI8 Oracle OvrimosSQL Paradox Firebird/Interbase (PDO) IBM (PDO) Informix (PDO) Oracle (PDO) ODBC and DB2 (PDO) SQLite (PDO)

GMP
SCA SDO SDO DAS XML
kadm5
ssh2
phar
FDF
Readline

4)The obviously useful, yet missing ones (i.e. the ones that, I think we need to add) are: gmp and readline

SUMMARY: most of the important stuff is now included in Gutsy. However, gmp and readline have been overlooked.
There are also a lot of PECL things, which are probably beyond the scope of this bug.